You can get teleporter pyramids after you reach the imp village in act 2 (actually north west of the village), and will have them up to the end of act 3.
If you are covering ground you have already cleared, try moving the screen focus so it isn't locked on the lead character, and then click on the mini-map to direct your characters. They will move faster if the game doesn't have to draw the scenery (set a hotkey to re-centre the screen focus). With the game running normally it isn't a huge improvement, but since you are experiencing a slowdown, maybe that will help more.
There are speed penalties for certain weapons and armour, though some can have speed bonuses, as well (as can jewelry). It isn't really a huge effect, though, so you don't need to agonize over choosing stronger armour that is slower vs weaker armour that that is faster, etc. Put a couple extra stat points into Speed if you start having problems, or if you are using a bow/crossbow max the Reload Time sub skill for the associated weapon expertise.
Fergus on the first level dropped a book that teaches Identify to level 2; when you reach the drill grounds in the citadel, the weapons officer teaches it to level 5. Nobody teaches it in act 2. In act 3 the smith in the temple also teaches it to level 5. Brian in the BF of act 4 teaches level 10.
