Lets break this up a bit
Few questions:
Why does version 7 come with vc stock kernals?
the developers decided that it was important to keep up with the times
Why isnt there reboot buttons on the power putton menu like the ThundeRom theme?
most people only need to reboot into recovery and adding those lines of code is more work then the devs wanted for something thats as easy as pressing three buttons
How exactly do i install the deluxe rom after i have already installed ThundeRom v7?
by "deluxe rom" i'll assume you meant the deluxe build.prop, and you flash it just like you would the rom, go into recovery, flash from zip, and select the deluxe build.prop, once its done restart the phone. THE BUILD.PROPS ARE NOT SEPARATE ROMS AND DO NOT ERASE YOUR CURRENT ROM THEY JUST CHANGES SETTINGS.
Like, do i have to clear cache and davlik for it to become effective?
first drop "like", its just an instantly repulsive word, second you do not wipe anything when flashing a build.prop. I would recommend that you flash your rom boot into it, then reboot to recovery, flash 1(ONE) change, then restart, repeat. Though it may work many times for many people, if you flash a rom and then flash a bunch of changes before ever booting the phone, you'll never figure out what may have gone wrong if you have a problem, and it will make troubleshooting your problems difficult for those you ask for help.
On this note, its been bugging me for a bit, ksmith or beezy if you read this, i'd like to recommend changing the name from deluxe build.prop to something else, i think people are getting caught up in the name deluxe and are expecting too much from it. i don't know if it's changed but if i remember you used to have one labeled jit one for stagefright and deluxe, but instead of deluxe maybe the name both would be better? Not going to tell you what to do with your rom, but two people in two days just jumping straight to deluxe without research, seems like it's probably just the flashy name.