I'm not sure Patreon money is considered income; I believe most countries considers it a donation. Kickstarter/Indiegogo, is considered Investment Capital, and that can be taxed, but donations generally are not. Income implies that you delivered on something and received payment in turn; ie if you are a plumber and you do plumbing work and get paid for it, that is income. As Patreon doesn't actually imply that you have to deliver on anything, I don't think their money is taxable.
Developers often want an office space because then they can have a communal game room, where people can unwind between development bursts. Developing is a burst-type of thing, where you get something done for an hour or so, and then need a break before another burst. Developers that try to maintain a longer burst, often will make mistakes that will require them to go back and fix things after the fact.
Also 42k a year for a developer in Germany is very low. The average programmer in Germany makes between 90 to 110k. 42k may be a liveable income, but when other jobs are basically offering double of 42k, it wouldn't make sense to pay them 42k.