There are two classes of slow-playing that I've seen.
1) The deliberate slow-play. This is the case where a guy takes a minute to roll dice despite having only one legal target. You usually know it when you see it.
2) The "accidental" slow-play. This is where the player takes forever to set up moves largely due to indecision. There's one player who developed a very bad reputation for slow-playing (taking forever to plan moves despite only flying a two-ship list). But, having watched his games, I don't think he was deliberately trying to slow the game down. He wasn't avoiding combat. Indeed, in a Dash vs Chewie battle, he repeatedly would barrel-roll his Dash to get a shot at Fat Chewie, even though he was winning on points and had nothing to gain beyond keeping the combat going.
#1 is a problem, but #2 is common enough when players start to try to out-think their opponents. They'll set their dials down, then realize a counter-move, then change their dials, then realize their change was stupid, then change it back, then realize they forgot to account for potential blocks and change it again. I don't know a player who hasn't done that.
You also have some players under the impression that playing defensively is also slow play. As the op mentioned he was accused of slow play by simply keeping to the edge which IMHO is incorrect use of the term.
Slow play is not playing. It is taking long time to set dial roll dice or deal damage or take actions.
Defensive playing is moving out of range keeping away from enemies, delaying engagements for a few turns. Forcing them into positions that if they engaged they will be at a disadvantage. However that is playing the game. Sure they are not getting into blaster range as fast but that is still playing the game.
People need to get it into their heads what actually is "Slow Play"
Edited by Marinealver