Good. So you don’t know if you will even get 3.8% for 30 years. Since your loan has to be finalized in 3 weeks, that is actually not an option.
Our communication with the bank always takes 3-4 days per cycle. That means the bank sends a letter along the lines of "We cannot disburse because blablabla is missing." Then you submit something, which takes another day with the mail, processing, feedback by mail...
In the current situation, I do not consider 10 years to be Russian roulette. Does anyone here really believe that interest rates will be at 5, 6% in 10 years?
How is that supposed to work? Then, interest payments alone on the federal debt would mean more than 100 billion EUR...
Or you wait... currently, interest rates are on the way down. Financing now in a rush with 3.8% for 30 years and 1.2% repayment is, in my opinion, not a good idea. Will you even manage to pay that off during your lifetime with the repayment?