Lifeform maxed out ?

You have already reached the 50% crawler production cap. As crawlers are capped at producing 50% of your mines output, this research will not increase your production, only decrease the crawler energy consumption.

I would assume so. Discoverer/general get 0.02% for every crawler, while collector can boost to 0.045%, and use 10% more crawlers if you have geologist. With every mine level, you get to use 8 crawlers, so it's going to be a bit hard to hit 50% without collector. If you plan on switching back to discoverer/general, then maybe it's worth it. Though you can't rebuild crawlers, switching classes is going to be expensive. You can wait for free class tokens, then you have a useless research for however long it will take.

The research is bad if you plan on staying collector, the mecha one is better.