Hola, so for speedrunning im look at https://www.speedrun.com/infested_planet on a any% normal difficulty.

for strategies yes. there is a few layers you need to consider for actual strats
1) how to spend money and when to spend money. learning exact money amounts for buying addditional troops at certain levels to give you a few second boosts in game time compared to sitting on resources is actually really important for the first few levels ( wont give away my strat till i post my run)

2) there is a guide out there that shows you how to do every single level. i recommend reviewing that guide and repeating each level 3 times over just so you get an understanding of the mechanics of the level and know what you're suppose to be doing. once you do that. try different troop compositions. do you want to have 2 additional marines to push a hive at the start? or do you want 1 shotgun 1 marine? and all the small details, you can refine those in each level to reduce seconds in each level

3) cant stress the importance of hotkey. learn them. rebind them to what ever you need them to be. but use them. control group your marines. learn how to control two groups of marines at one time. learn to bounce your camra with hotkeys and control those two groups of marines. or just basic hotkeys to quickly upgrade / demote / etc etc

4) managing helicopter strikes is HUUUGE. once you know the maps, learn what pushes you can spam heli strikes or not.

this community is real small at the moment, so i really just encourage you to keep with it :) there is a few out there. but nothing much, just submitting runs and getting your own info out there can be a great help :D