自分の書いたFirebaseのsecurity ruleが本当に安全か知りたい、アドバイスをいただきたい

実現したいこと

自己開発のマッチングアプリの開発にfirebaseを使っています。リリースするにあたり、セキュリティが本当に安全かどうかを調べたいです。

発生している問題・分からないこと

自己流で書いてみたのですが、いまいち自分のコードの安全性に自信が持てません。アドバイスなど頂けたらありがたいです。Security ruleと主にfirebaseの情報に変更が起こるところのソースコードを載せておきます。他に必要なソースコードがございましたら教えて頂けたらありがたいです。

該当のソースコード

Security
1rules_version = '2';
2service cloud.firestore {
3  match /databases/{database}/documents {
4
5        // 切り出した関数の記述
6        function isAuthenticated() { // 条件 1
7            return request.auth != null;
8        }
9    
10        function isUserAuthenticated(userId) { // 条件 1 かつ 条件 2
11            return isAuthenticated() && userId == request.auth.uid;
12        }
13        
14        // function isAdmin() {
15        //   return isAuthenticated() && request.auth.token.admin == true; // Assuming 'admin' is a custom claim you've set
16        // }
17
18        // ユーザーデータのスキーマ検証
19        function isValidUser(user) {
20            return user.size() == 3
21            && 'createdAt' in user && user.createdAt is timestamp
22            && 'email' in user && user.email is string
23            && 'userId' in user && user.userId is string;
24        }
25        
26        
27        function isValidUserFS(user) {
28            return user.size() == 12
29            && 'bio' in user && user.bio is string
30            && 'cur_matching' in user && user.cur_matching is string
31            && 'done' in user && user.done is bool
32            && 'facebook' in user && user.facebook is string
33            && 'imageLink' in user && user.imageLink is string
34            && 'instagram' in user && user.instagram is string
35            && 'matchings' in user && user.matchings is list
36            && 'phone' in user && user.phone is string
37            && 'preference' in user && user.preference is string
38            && 'sex' in user && user.sex is string
39            && 'username' in user && user.username is string
40            && 'wait' in user && user.wait is bool;
41        }
42
43        // ルールの記述
44        match /users/{userId} {
45
46            // ユーザー情報の取得のルール
47            allow get: if isUserAuthenticated(userId);
48
49            // ユーザー情報の作成のルール
50            allow create: if isUserAuthenticated(userId)
51            // スキーマ検証
52            && isValidUser(request.resource.data)
53            // データのバリデーション
54            && request.resource.data.createdAt == request.time 
55            && request.resource.data.userId == userId;
56            
57        }
58        
59        match /Users/{email} {
60          allow read: if isAuthenticated();
61
62          allow create: if isAuthenticated() && isValidUserFS(request.resource.data);
63
64          allow update: if isAuthenticated() && isValidUserFS(request.resource.data);
65        }
66        
67        match /Female_match_stack/Counter {
68          // Rules for 'Counter' document
69          allow read, update: if isAuthenticated();
70        }
71        
72        match /Female_match_stack/{document=**} {
73          allow read: if isAuthenticated(); // Only authenticated users can read
74
75          // Allow updating only the stack array, and only allow adding the user's own email
76          allow update: if request.auth != null && 
77                         request.resource.data.stack.size() == resource.data.stack.size() + 1 && 
78                         request.resource.data.stack[request.resource.data.stack.size() - 1] == request.auth.token.email;
79          
80          allow create: if isAuthenticated();
81        }
82
83        match /Male_match_stack/Counter {
84          // Rules for 'Counter' document
85          allow read, update: if isAuthenticated();
86        }
87
88        match /Male_match_stack/{document=**} {
89          // Rules for all documents under Male_match_stack other than 'Counter'
90          allow read: if isAuthenticated(); // Only authenticated users can read
91
92          // Allow updates only if adding to 'stack' with the user's own email
93          allow update: if request.auth != null && 
94                         request.resource.data.stack.size() == resource.data.stack.size() + 1 && 
95                         request.resource.data.stack[request.resource.data.stack.size() - 1] == request.auth.token.email;
96
97          allow create: if isAuthenticated();
98        }
99    }
100}

Flutter
1Future<void> editCondition() async {
2    User? currentUser = _auth.currentUser;
3    if (currentUser == null || currentUser.email == null) {
4      return;
5    }
6    DocumentSnapshot userDoc = await _firestore.collection('Users').doc(currentUser.email).get();
7    DocumentSnapshot counterDoc = await _firestore.collection('Male_match_stack').doc('Counter').get();
8
9    String gender = userDoc['sex'];
10    String collectionName = gender == 'male' ? 'Male_match_stack' : 'Female_match_stack';
11
12    await _firestore.collection(collectionName).doc(counterDoc['num'].toString()).update({
13      'stack': FieldValue.arrayUnion([currentUser.email])
14    });
15    await _firestore.collection('Users').doc(currentUser.email).update({'wait': true});
16  }
17
18  Future<void> makeMatch() async{
19    CollectionReference counts = FirebaseFirestore.instance.collection('Male_match_stack');
20    final counter = await counts.doc('Counter').get();
21    final cur_cnt = counter.get('num');
22    CollectionReference males = FirebaseFirestore.instance.collection('Male_match_stack');
23    final male = await males.doc(cur_cnt.toString()).get();
24    final maleStack = male.get('stack');
25    int maleLeng = maleStack.length;
26    CollectionReference females = FirebaseFirestore.instance.collection('Female_match_stack');
27    final female = await females.doc(cur_cnt.toString()).get();
28    final femaleStack = female.get('stack');
29    int femaleLeng = femaleStack.length;
30    final new_cnt = cur_cnt + 1;
31    FirebaseFirestore.instance.collection('Male_match_stack').doc('Counter').update({
32      'num': new_cnt
33    });
34    FirebaseFirestore.instance.collection('Female_match_stack').doc('Counter').update({
35      'num': new_cnt
36    });
37    if (maleLeng.isOdd){
38      maleLeng -= 1;
39      FirebaseFirestore.instance.collection('Male_match_stack').doc(new_cnt.toString()).set({
40        'stack': [maleStack.last]
41      });
42    } else {
43      FirebaseFirestore.instance.collection('Male_match_stack').doc(new_cnt.toString()).set({
44        'stack': []
45      });
46    }
47    if (femaleLeng.isOdd){
48      femaleLeng -= 1;
49      FirebaseFirestore.instance.collection('Female_match_stack').doc(new_cnt.toString()).set({
50        'stack': [femaleStack.last]
51      });
52    } else {
53      FirebaseFirestore.instance.collection('Female_match_stack').doc(new_cnt.toString()).set({
54        'stack': []
55      });
56    }
57    if (maleLeng>1){
58      for (int i = 0; i<(maleLeng/2); i++){
59        FirebaseFirestore.instance.collection('Users').doc(maleStack.elementAt(i)).update({
60          'cur_matching': maleStack.elementAt(maleLeng-1-i),
61          'matchings': FieldValue.arrayUnion([maleStack.elementAt(maleLeng-1-i)]),
62          'wait': false,
63          'done': false
64        });
65        FirebaseFirestore.instance.collection('Users').doc(maleStack.elementAt(maleLeng-1-i)).update({
66          'cur_matching': maleStack.elementAt(i),
67          'matchings': FieldValue.arrayUnion([maleStack.elementAt(i)]),
68          'wait': false,
69          'done': false
70        });
71      }
72    }
73    if (femaleLeng>1){
74      for (int i = 0; i<(femaleLeng/2); i++){
75        FirebaseFirestore.instance.collection('Users').doc(femaleStack.elementAt(i)).update({
76          'cur_matching': femaleStack.elementAt(femaleLeng-1-i),
77          'matchings': FieldValue.arrayUnion([femaleStack.elementAt(femaleLeng-1-i)]),
78          'wait': false,
79          'done': false
80        });
81        FirebaseFirestore.instance.collection('Users').doc(femaleStack.elementAt(femaleLeng-1-i)).update({
82          'cur_matching': femaleStack.elementAt(i),
83          'matchings': FieldValue.arrayUnion([femaleStack.elementAt(i)]),
84          'wait': false,
85          'done': false
86        });
87      }
88    }
89  }