Round the edges of the plates. Then round them some more. Then sand them smooth. Otherwise, they'll chew up your co-LARPers weapons like they were going out of fashion.
Consider riveting or soldering the rings shut, once everything is in place, otherwise you'll spend quite a while re-closing them after each time you've taken the armour out and about.
Before you take it to a game, build up to however long you'll be needing to wear it. Put it on for fighter practice, walk around in it, wear it. But do this starting from a short period of time, building up to however long you'll need to wear it for. Also, you move different with armour on than without the armour.
Make sure you have some sort of padding underneath. Any hit on metal armour that's resting on skin (or skin only covered by thin clothes) hurts, a lot.
Weight is less of a problem than heat. All that padding keeps you warm. That makes you lose water. Heat-stroke is likely and no fun (seriously no fun, as in "it can kill you"). But if you build up the time you wear the armour slowly, you should easily be able to adjust your water intake.
Some details about rings (specifically for maille, but probably relevant for banded mail as well). Rings made from wire can be finished off in, essentially, three ways. Butted, riveted or soldered/welded.
Butted rings are simply closed and held in shape by the material in the ring itself. This is quick and easy to make, but for rings that use a thin wire in relation to the ring diameter it leads to the rings opening and possibly unlinking themselves from the stress of being worn and hit.
Riveted rings uses a slight overlap of the two ends of the wire, pounded flat, with a hole punched and a rivet beaten in place. These may deform under stress, but rarely (if ever) come open.
Soldered/welded rings are butted rings where the join have been touched off with an oxyacetylene flame and possibly a small touch of solder. It's much quicker than riveting rings, but really isn't how it was done "back in the day". However, it affords a quick way of getting butted maille that can stand up to the stresses of full-on impact.
