House construction / house purchase planned, evaluation of financing plan

So, I’m speaking up again after a long time. In September (yes, everything is taking a very long time) the notarized contract for the plot of land was signed. Property transfer tax and land register fees have already been paid; I’m still waiting for the invoice from the notary.
As of today, the building area is still not developed, there are not even construction roads yet. However, these are supposed to be completed this year.

I arranged the financing through my house bank, consisting of three components (2x KFW and the rest from the house bank). Since the contract was only signed a month ago, commitment interest charges will only be due starting October 2022. Before that, of course, interest on funds already drawn down. I find the conditions quite good for 100% financing: 1.35% effective interest with a repayment rate of 3.08%. The monthly installment is around 2100 euros.

Interest depends on whether it is for 10, 20 or 30 years...

For understanding: The total rate (1xBank, 2xKfW) amounts to €2100. Interest + repayment only refer to 1xBank, right? What volume and what fixed interest period are we talking about here? The numbers cannot be evaluated like this.

Very risky if the construction road and development are not yet in place. Now for understanding. Did you take out financing for the land and the house? If yes, see above. Developments can drag on for months/years and then the building application still has to go through, or do you already have the building permit?

Exactly, 2100 euros per month for the three financing components. The two KFW loans are fixed for 10 years and the loan from the Sparkasse for 15 years. Total volume just under 560k. The amount is for the plot, house, and additional construction costs. I was assured in writing that the construction road should be completed this year. Unfortunately, the building application can only be submitted once the construction road is finished and the plot is thus "accessible".