I damaged the rental RV during the trip, will I get my security deposit back?

Depends on the nature of damage. If damage is minor then it will be deducted and rest of your security deposit will be returned. However if damage to rental RV is significant and exceeds your security deposit then you will be required to pay additional balance till you meet your deductible. E.g. if your security deposit is $1000 and damage to RV is $3000 and your deductible is $1500 then you will need to pay an additional $500 tpo meet your deductible and then the RV insurance kicks in to cover rest of the rental RV damage.