Against Nids and Orks you want Flamers, High S blasts, ML's, Plasma and high ROF weapons (AC/HB), GL's even.
Not taking SW's in the PCS's is missing a trick..4 slots gone begging. 3/4 Flamers works great in a Chimera..they can react quickly to any enemy units advancing on your line.
Mixing SW's within a single Squad doesn't work as effectively as taking all the same ones, so I would take GL's only in the Inf/Squads...Plasma should be on BS4 minis.
I see all-Lascannon HWS's and think Vendetta..far more effective and more bang-for-your-buck. But like I said earlier these would be better as AC or HB..at least take some.
Sorry, but I think Sniper Rifles should only be on Ratlings - they're cheap so you can take more of them, and they are BS4 and get decebt Special Rules that help them get into a favourable position.
The rifle isn't that good really on a BS3 model..4's to hit and to wound.
Punishers look good on paper, but even against weak enemy they will disappoint you most games. Against Hoards it will get maybe 2 turns of shooting before they swamp it and destroy it in c/c, and it will likely have only killed 15. You'd be far better off with a LRBT..the blast will kill more for longer.
My 2c anyway, best of luck with it