SS, I actually have british citizenship but I was born and raised here in Germany mainly speaking German, going to german schools, having german friends etc. I even learned English in a german school, really, but maybe I had more interest in it than your regular German plus we did have lots of BFBS/SSVC on at home so that may have subconsciously helped. I also spent 3 1/2 years in the US as a young adult where I certainly improved my skills but picked up an unbearable accent (for brits such as my dad, at least

Anyway, I went to the UK quite often during my life (mostly London area because I wasn't interested in the landscape as a kid, so to say) and also had many curries there. That's also what prompted me to research this whole BIR thing since what I was getting and making over here just didn't do it for me.
As for the german palate: I really don't know, as I neither consider myself purely german nor british (I wouldn't even know whether to feel 'english' or 'scottish' like my dad as I wasn't born in the UK, lol). I have noticed that Indian Restaurants don't appear to be very popular, though. That was certainly different just a few years ago when we had several thousand british soldiers in town.
Today, on a week day these restaurants can be glad if they have 15 guests in the evening hours - for the 'Taj Mahal' I think that would be a high amount even on the weekend despite its central location. The 'Sangam' is actually in a little village and a fairly posh Restaurant. The only one for miles, so it's fuller. One thing is pretty evident, though: most Germans don't like very hot or even very spicy food very much. There are always exceptions to the norm, of course. But whereas the stereotypical brit might get mashed at the weekend and top that evening off with a 'as-hot-as-ya-mama-makes-it' Vindaloo, your stereotypical German would probably choose a D