Altering any part below 100% is forbidden to use in combat (straight advantage over non-VIP players).
Resizing hands above 100% obstructs the enemy's screen and is forbidden.
sm_resizeme if used by itself (i.e: all body parts still at 100%) will reflect the correct hitbox. Therefore, resizing yourself bigger will give you a disadvantage: it is allowed in combat.
Torso/head resize doesn't reflect your real hitbox: any modification is not allowed in combat
Reminder: these commands are here for fun.
Admins are also subject to these rules. If you see a staff member not respecting the above, gather evidence and fill out a staff abuse report.