Depends on quite a lot of factors, such as flop texture, opponent, positions etc.

Try and make your question a little bit more specific because this question is way to broad to get a answer that will suit your needs.

Yeah, this question is a little too vague I think. You're better off posting some individual hand histories and asking for advice OR adding to this post and putting in some specific board textures or player types that you struggle playing against with these types of hands.

Sorry guys for the vague question, I have updated the question and hope you can give me some advice.

You could write an 100000 page book on the subject. Solver is your friend.

Q1: Not very often. You should mostly fold, perhaps 4bet againts certain opponents.

Q2: You can cbet most flops, especially if you have something going on with your hand. With bottom pair you generally want to cbet or check/call, rarely check/fold. With top pair both check and bet are viable, depends a lot on who you're up againts etc.

Q3: The answer is quite similar to the previous answer, but you obviously want to play slightly differently with tighter ranges.

Question 1: Almost always fold and then depending on how you build your 4 betting range you might be able to 4 bet sometimes. Calling a 3 bet in this situation isn't going to be profitable.

Question 2: Try to think about how you want to play your range in its entirety on different boards rather than specific hands. In the age of solvers, you're going to have lots of boards in these situations that you want to make a 1/3 pot or so bet with your entire range and then on the turn start to think more about what specific hands to bet.

Question 3: This is similar to last question where you're going to want to create a gameplan for how to play certain board textures with your range rather than specific hands. If you're looking to make exploitable plays in these situations you need to think about how wide your opponent calls 3 bets, if they call flop cbets liberally, are they likely to call a 2nd barrel with worse hands, if you check back the turn are they likely to bluff the river, do they even have hands in their range that want to bluff the river?

I'd highly recommend that you watch a few hours of some of our SSNL content to get a feel for how some of these decisions are made in game. Here's three video recommendations to start with:

50 NL live play video from Cameron Couch

50 NL live play video from Iain Salter

50 NL live play video from Paul Atwal