TL;DR: option 2.
One piece of advice you will often be given here is that waiting for a market downturn to happen is essentially the same as gambling on market timing, in other words, it is not investing, but it is speculating.
Some five or six years ago, I would not have fully agreed to this statement, but now I do. After refraining from investing for about 3 years, waiting for a what I thought would be an inevitable downturn, which did not come (but will surely now!!11 Haha, right. No way of knowing.), I finally started investing, expected up- or downturns be damned.
But I also am/have been scared to invest any built-up savings in one single moment in time, so I've chosen to invest regularly instead. The jury of whether the accompanying cost-averaging is actually better (regarding gain and risk) than investing in a lump sum is still out there, but it just gives me more ease of mind. I am shifting the ca. 30-to-70-distribution between investments and cash towards a set goal distribution over time.
My suggestion would be:
1. Max out the Bausparvertrag and stick it out as long as you can (but avoid making it ready to pay out early, "Zuteilungsreif")
2. Determine what goal distribution between investments and cash you want (e.g. 10.000 in cash, rest investments)
3. Determine how long you want to smooth out the transition (longer if you are scared of a crash, shorter otherwise). Longer means that you forgo returns in exchange of the ease of mind, however.
4. Build your investments, partially from income (the ~1.000), partially from cash savings
5. Keep it on autopilot (with yearly rebalancing) and *avoid to regularly check how your investments are doing*
I can't say much about option 3, but it sounds more like part of work to me than personal investing.