Improving the default behaviour in TFpPascalPrettyPrinter.InternalPrintValue for AValue.Kind = skAddress could be to either do a memory dump, or to call DoUnknown. Defaulting to memory dump is what I would expect, but at least calling DoUnknown would return a valid error (Unknown type...) rather than the current cryptic <invalid>.
Yes, that would be ok.
Can you bug report those issues, so they want be forgotten?