What rolls would be needed for a Psion to use Telekinesis to move a grenade to make an attack, in particular, to make a sneak attack? i.e. put a gas grenade into a room.
If you are just lobbing it, then Telekinesis rules applies:
"Using the
Hurled Attack Tier-specific and Mass abilities, the adept can hurl
one object telekinetically at a target per round, making a Physical
Attack using the skill bonus in this Discipline as the OB on the
Crush or Impact Critical Tables (SysOp’s discretion)."
For subtle work, use Telekinetic Hand with Tiering for range and finesse (and apply the finesse penalty to the skills used by telekinetic proxy).
Bolt attack - how far away? Can you use telescope to 'spot' target that is line of sight and is there a range penalty?
Bolt attacks have range set as Standard so the range of a Bolt is set by its Tier (1 = 1m, 2 = 1m/rank, etc.) see Table 11.3
Best wishes,
Nicholas