1. Yes
2. Yes
3. Yes
While I don't have the Epic, my KRL riser is quite sturdy, and it is one of the older bolt-together risers. The new ones are one piece.
I have a overhead locker as well loaded with a balljoint press, tap & die set, thread chaser set, compression gauge set, vacuum gauge set, fuel pressure gauge set, manuals, welding helmet, and so on. Probably around 150 LBS. of tools and **** at around 7 feet tall. I have noticed zero deflection or racking. Also, my riser is screwed to a maple top with a few screws.
I've got three slots-n-dots shelves, a hammer rack, and a document holder mounted on the back wall. One shelf is loaded with about a dozen spray cans. The is some deflection on the back wall, but whatever. You'd have to seriously over load those little shelves to cause any damage to the riser. The shelves would give way before that happened anyway.
I highly recommend an overhead locker if you can swing it. Yes, it's just a big, empty box too, but it helps get all the bulky **** that you don't use everyday up, and out of the way leaving you a nice work area.
