I'm giving Frontier a try as the intra-Calif fares on Southwest have become ridiculous. Frontier seem to be relatively on time and I have flown RyanAir, so totally ok with all the fee rules.

I know the checkin at LAX is at T1 but the gates are at TBIT. Assuming I just have a personal item can I just go through security at TBIT and that will be faster?
Has TSA Pre been working ok on Frontier?
Anything else I should be aware of flying them?