Kelp Dome is the smallest map iirc.
Isn't it the largest? o:
Pretty sure Blackbelly is the smallest.
Turf War and Ranked should honestly all be used, but have them be in different systems, since what you are trying to accomplish dfferent things in the modes. Squads could/should have different win/loss records: one for Turf War and one for ranked.
Something I'd like to suggest for competetive Turf War is to have the winner decided through the cummulative total of turf inked between the rounds instead of best out of x matches. Having it be cumulative represents the mode and fits better in my opinion. The whole point of turf war is to cover the most turf, right?
In this way, even if a team loses the first x matches by a little, they still have the possibility of winning/catching up if they have a dominant match later on.
Also having it be cumulative makes it so people will play up until the very last second, instead of just quitting the current round after being pushed back to their base with no way of winning at that point. Every single bit of turf would matter. People may also attempt to guard a large portion of the match with best out of x matches, attempting to secure an easier win. Cumulative totals makes it so that that strategy is not as effective.
Considering each match is ~3 minutes, and lobby time would probably be around ~1 minute, I'd suggest having 7 rounds in each squad battle, resulting in each battle being around half an hour.
Just an idea. :P