Apparently, my strategy is not that simple. In very simple terms: I do not want to contribute 200 or 300k as equity. Additionally, I can save about 42k without interest in the first 5 years. Instead, I want to repay as little as possible and let the capital markets work for me. The interim volatility (+2-7%) should not concern an investor. We are talking about investment horizons of at least 10, preferably 20 years. I think transferring the portfolio is nonsense. If I become insolvent, I will be liquidated and file for personal bankruptcy. The property will be liquidated.
My question was how the bank reacts to such financing or "what you need to bring."
My wish (I am currently leaning more towards my Alternative 2):
240k (2x 120k KFW, 96k must be repaid. 0.95%, 5 years repayment-free, term 30 years, burden with repayment 2x 396€)
260k bank loan, 20 years, 1% repayment, interest of 1% is possible according to the internet, burden with repayment 434€/month.
In total monthly burden 1226€/month after the 5 repayment-free years.
Remaining debt after 20 years 208k bank, 2x 38400 with KFW.