I have 3 questions,

1) Is there any limit (any percentage) in hike in the rent on a house rental lease renewal in Florida?

2) Can I claim my security deposit (which is much higher than normal deposit as initially I didn't have rental history/credit history) during lease renewal?

3) Can I bargain on the renewal rate if my credit history improved during this year?

1. I don't know

2. Claim secuirity deposit for what?? Security deposit is just that, you can ask for it to be reduced for your past years good record. Personally doubt that it will work but what the heck try

3. Always bargain, never accept anything without trying to bargain.

NO

NO

You don't want to do this. In order to prove your credit has improved, your landlord would have to re-run your credit which can actually LOWER your credit score to other creditors

If you are expecting a large renewal rate, arm yourself with comp property rents in the area and have a discussion with your landlord.

1) Check your local laws. There may be some limits in the percentage raise. If there is it's a matter of local law, may not even be on the state level.

2) Claim for what? You paid the security, its purpose is primarily to recompense the landlord if you leave the property damaged with a secondary purpose of covering them if you skip out. As Chcuk said, you might be able to negotiate a return of a portion of it, but its unlikely.

3) Your credit rating and rental have nothing to do with each other. I can see a landlord asking for a larger security deposit if there is no record on you, but the rent has nothing to do with that.

If the new lease include an out of the line increase, you can go to the landlord showing comparable rentals, but they can just respond; so move there.