Truth is the housing system is old outdated and doing things it was never designed or ment to do. It needs a complete overhaul from top to bottom but it has likely been a less important/popular part of the game and the developers haven't spent the time/resources needed to redo the whole system.

As far as the items you lost go they are all possible to get again, even the seasonal ones. Some items will require the help of other players and jumping through hoops. But if you really want them and it means a lot to you it is possible.