1.Stats: Should Torterra get a stat boost, Evolution, Mega Evolution or nothing?
Torterra can get at most +15 BST.
Torterra can get a side evo, but it would mostly prefer a Mega. Its stat distribution is outdated, so it would like a better one.
2.Should Torterra get more abilities?
Yes. Chlorophyll, Sheer Force, Sand Force are all options.
3.Should Torterra get more moves?
Moves like Power Trip, Zen Headbutt, Head Smash, Psychic Fangs, Gunk Shot, and Barrier should be options. Shell Smash would also be good.
4.What additional typing Chesnaught can have?
Dark, Fighting, Steel and Rock are the obvious options.