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Hard to answer the 1st question unless you know more about the car. If you're asking based soley on mileage, I'd say it's not necessarily a factor. BMW's are known to run high mileages if taken care of reasonably. Keep checking back, as some of the E34 guys here may be able to offer some insight on what to look out for when considering this purchase.
The front plate delete is a bumper strip replacement that eliminates the area where the plate goes.