Pike are good from clean cold lakes at any size... But the smaller ones don't carry much meat, say below 22 -24 inches.
Come to Nip with me and I'll get u into some good Ling, herring and Perch... First hand knowledge is the best.
Any speck is good eating, but keep in mind the populations (natural) are sensitive.
As for bass... Well, keep them all, make room for more walleye and trout. They taste good from clean cold lakes as well.