SALESFORCE LIMITATIONS AND BEST PRACTICES

 Sharing Rules :

The limit is across both Standard and Custom Objects as 300 Maximum rules with 50 Criteria Based rules on Enterprise and Unlimited/Performance Editions only.

You can create up to 50 criteria-based sharing rules per object.

Note :

On an object where the OWD setting is 'Controlled by Parent' you will not be able to set up sharing rules, so you need to change this, 

e.g. On Contact to either 'Private', 'Public Read only' or 'Public Read/Write' to add sharing rules on this specific object.

As a best practice, keep the number of ownership-based sharing rules to 100 per object, 

and keep the number of criteria-sharing rules to 50 per object.

Note : 

1.Removing an Account team member doesn't remove an Opportunity team member.

2.Know that platform out of the box 'implicit' sharing doesn't apply to Apex sharing.

3.You can create up to 10 Apex sharing reasons per custom object.

Not Possible with permission set :

The only things that must to be controlled by Profiles and can't be structured in Permission Sets are:

Page Layout Assignments

Desktop Client Access

Login IP Hours

Login IP Ranges