It's pretty balanced when you take into account cost/survivability.
The only things that are remarkable about T-70 is its low manpower cost compared to other vehicles (200!?) and its pretty overall awesome moving accuracy.
If it needs anything its a slight change to either of those .I would say moving accuracy to make it less of an obnoxious circle strafe doom machine that can chase down retreating squads and wipe them more often than pretty much any other vehicle in game. But when you take into account its HP it's your prototypical glass cannon so it's, once again, more or less fine as is.
I would like to see MP increase to 240 or 280 or 300 and increase Hp to fit the other light tank