Rent out or sell a condominium? Decision in times of crisis?

Dear Forianers,

I need your personal assessment, opinion, advice on the following situation.

I have a condominium that I am currently in the final stages of clearing out and advertising for rent. I have already conducted a viewing with an acquaintance, and afterwards, he asked me if I would also consider selling. I initially said that I wouldn't categorically rule it out but would need to think about it again.

Background: I bought the apartment in 2016 and then refinanced it to raise capital for building a house. That means it is now encumbered with about
approx. 150,000 EUR old loan, interest rate 2.3%, fixed interest until 2030, expiration of the 10.5-year period in 2026.
215,000 EUR new loan, interest rate 0.81%, fixed interest until 2030, expiration of the 10.5-year period likewise.

Valuation 2019 (Sprengnetter) 462,000 EUR. (presumably less now?)

Let's say I agree on 430,000 EUR and he can also finance it. Then a balance of 65,000 EUR remains. A nice profit on top, tax-free since the apartment was last owner-occupied. Possibly there will still be early repayment penalties from the two banks, but that probably shouldn't be much thanks to the now increased interest rates, right?

So now I’ll write down the pros and cons of selling with mitigating comments:

Pro:
- A bit more money left to put into the house (photovoltaics?)
- No administrative effort with the apartment, including maintenance
- No more unexpected special assessments
- No trouble with problem tenants (my acquaintance is a teacher and quite reliable)
- Viewed as an investment, no longer a concentration risk (if invested in the house, the same risk; do I really want to invest the money?)
- Possibly avoiding the imminent loss in value (which I actually don't believe for Berlin)

Con:
- No more retirement provision (I don’t mean possible rental income but a possibility to move back in during old age, which I probably couldn't afford otherwise)
- If the marriage ends after all and the house has to be sold, no more home ownership at all...
- No further participation in value increases

Have I forgotten anything?
My head says: Sell!
My gut says: Keep!
My wife says: rather sell, but okay with everything (the apartment belongs only to me even in case of divorce)

Clearly, I have to decide in the end, and it always takes two yes-sayers.
But still: How would you decide?

- How old is the condominium and are there foreseeable costs for you due to energy-efficient renovation, heating replacement, etc?
- Are you able to achieve an appropriate return through renting? Measured against the 430k you currently estimate as the value
- Do you want to be a landlord, with all the consequences?
- Do you want to be a landlord among acquaintances? ("Money ends friendship")

Thank you for the additional questions I will simply write down answers, this is not a targeted rebuttal. - The condominium is also 6 years old, I practically moved in as it was newly built. Nevertheless, the owners' association (WEG) has already had two special assessments: one due to unresolved defects, one for the renovation of the 100-year-old retaining wall to the neighbor. The developer is practically no longer around (a successor company of a successor company abroad). - I assume yes, with the rent I proposed to the acquaintance the purchase price factor would be 29, which is still cheap for Berlin. According to the offer market, I could probably ask for more, but somehow it would feel wrong to me. - I would say it is in my nature to take care of something or someone. But honestly, I rather have no desire to deal with these owners’ association issues even once a year. - That’s why only an acquaintance and not a friend. The apartment would be perfect for my best friend (his son goes to a school one street away). But we both agreed that it’s too risky for us. And the same problem would arise with a sale anyway, possibly even worse if a defect were to appear and then there was a dispute about whether it was already known. And suddenly it’s about half a million including incidental costs.

I would probably try to sell half....

I don't understand that. Sell half of an apartment? And then? Why?

Why are you expecting a divorce? Are you having a marital crisis?

Well, I'm not really expecting that. Death, yes, that can always happen. But I don't base my decisions on the course of the marriage. I find that kind of thing strange.

And what does your wife say about your concerns regarding a possible divorce?