House financially feasible at about 5,000 net?

Basically yes, but I rather believe that it will only lead to a (significantly) slowed growth. Germany (except maybe Munich) was actually quite cheap compared to the rest of Europe before the pandemic. So there was also a huge need to catch up.

Prices are rising with us on a monthly basis In the construction area with us, prices of 8,000 euros / m2 are now being called, including parking spaces. No person can buy that as an income-producing property.....

So with single-family homes it’s a bit different, but with condominiums and developer-planned townhouse developments (today they’re also called townhouses) there’s also a huge amount of "New Money" from China, Russia, and Saudi Arabia involved. It doesn’t really matter if they stand empty for a while as long as they can be sold five years later with a 50% return, it becomes an attractive investment.

The interest rates are already rising noticeably
I'm curious if in 2 years after moving in I'll regret it because prices have fallen by 20%.

Realistic?

Certainly not unrealistic. Various financings will no longer be possible, yours is a great example of that. You are already repaying very little; let the interest rates rise by 1 percentage point or even 1.5%, then nothing will be repaid at all. And then demand in a certain price range simply won't be there anymore. Because I doubt that people will give up their expensive Audi to make the house still affordable ;)

Quite realistic.

Sort of. The prices might be lower again, but then you'll pay more in financing. In that sense, a house has always cost _roughly_ the same.

However, it matters for those who bought/built during low-interest phases and have to sell/refinance during high-interest phases and still have a high remaining debt...