[Q] Easiest method to root and get recovery on Z2 topic

Hey guys I have been using this Z2 for 2 months now and I hate the stock UI so what is the best way for me to get the tools necessary to put a custom ROM, I also have two other questions, what do I lose with unlocking the boot loader (if necessary), what ROMS should I put on it and could i get the lollipop update when it comes. my phone is on 4.4.4