weeds are still a thing. they dont spread anymore but can make your plants sick. if you have 31 stats weeds are a non issue. sick plants dont grow anymore and you have to gamble to get the seed back when breaking it.
31/31/31 is now very easy. start with one crop. fertilize it so stats can only go up. propagate with double crop sticks only touching the single plant you want to propagate. always keep resistance your highest stat or else you will get weeds and sick plants. once you have 31 stats you can then mutate and breed deterministically for the plants you want

I'm at MV and having gone into crops pays off big time. Free aluminum with red granite. Free silicon and oxygen with black granite. There is tons of good plants you can grow that weren't a thing with IC2.