questions before a LSP brushless project

[speedsecret]

Hi all

I'm new here and I will like to get your help to build my first brushless truggy .
i have allot of experience with electric RC but i never done any nitro to brushless conversion yet.

i want to convert a new HB LSP with a Novak HV maxx system
i know that allot of people don't really like this system but i think it will satisfy my needs.
i want to build this truggy for racing tracks so i don't care about the top speed or thing like that .

i think of getting the hv maxx with 5.5 motor and use it with a 4s lipo

now the questions
do you think the 5.5 motor is too fast for driving on track?

what pinion size should i use?

do i have to change more parts accept the brushless motor mount that i will buy from the site store?

how much running time i will get from 5000mah 4s lipo?

do i need a ubec?

thanks all
i really want to start build all ready