It's hard to be sure without seeing yours live, but while I'm not about to go sticking business cards into my cellphone I would say mine has a similar gap and has had it from the very beginning. I never once thought it was a defect, because - as I mentioned - it's perfectly normal for a cellphone to have space between the keys as well as the keys and the body.
As for the play, I think I've noticed the same thing. The top left corner of the keypad (softkey / home / calendar / d-pad) compresses slightly if you apply light pressure on it, without actually activating the keys. Other parts of the keypad do not do this. This has been reported by a couple of other Finnish E71 users, too.
I'm looking forward to hearing what WOM has to say about this. I'm inclined to think the "gap" is by design but the play is not (at least it's not supposed to be, since the rest of the keypad does not give the same way).
If your E71 has not been taken away yet, can you check the light leakage as per my instructions in my previous post to confirm the light is not actually leaking from the display?