It's a common practice when doing side-chaining using a compressor, the 1st useful advantage to use a different source than your main kick as the SC trigger is that you can have it going through the all duration of your mix without having to think about arrangement. For example in some parts of the mix you may have the bass playing but not the kick and if you need to apply SC to your bass it's handy to have this independent source as a trigger. Simply take care to mute the output or set it to "send only" inside live so that it's not audible in the mix while still available to use as a compressor SC trigger.
Reason for EQing is to shape the signal that's gonna trigger your compressor, this will have an impact on how the compressor reacts to the incoming signal. If you expand Live built in compressor you will see that you have EQ & filtering options available as well as some 3rd party EQ like Pulsar's 1178 that have built in EQ to shape the SC source.
So basically, the thing to keep in mind here is what signal you're sending to the compressor, the level, focused on frequencies and length of the SC trigger will definitely lead to different results. You can also use shorter kicks or even hats as SC triggers and following this concept you can have multiple SC trigger sources in one mix to suit your needs.
For Tech House mixes arrangement structure and parts, those A,B,C parts will be things like Intro, Chorus, 1st Drop, Break Down, 2nd Drop as the names are used in most genres.
There are a lot of Tech House tutorials on S.A website, simply perform a keyword search from the main tutorial page using the magnifier icon on the top right and type in "Tech House", you'll find courses from Rene Amesz, Alex Tepper, Vince Watson, Ekoboy ( Vangelis Kostoxenakis ), Mescal Kids and more as well as S.A very own Phil Jonhston.
Next to that there are also in-depth courses about compression in general, search for this as well.
You can have a preview and decide if you'd like to get the full course or get a subscription. Have you tried your 7 days free trial already ?
Templates can indeed be useful to learn more but if you just have the project launched inside your DAW and no guidance to complement it, it's sometime confusing and less helpful than following a full track made from scratch from class A producers and for the price of a bunch of those templates, you could probably get a full course or a minimal sub to S.A
Simple & honest recommendation here, not advertising anything
Also, back to SC and compression, there's a lot of different ways to achieve it and using typicall SC compression with compressors is not always the easiest one to control because it will all depend on your compressor type & the settings you dial in + all the above for the SC source. Nowadays there's a lot more easy ways to achieve SC compression using volume envelope shaper tools like LFO Tools, Shaperbox, Duck... Or dynamic EQ type of tools like Trackspacer.
Check those free to watch courses as well :
Hope this helps