Honestly I don't think most unis care that much about what GCSEs you took. They definitely care that you get like a 5 or above in English and Maths but otherwise subject wise they probably won't mind (do try and do very well in sciences though).
I did RE and French (I know it's not german but my experience of a language) with WJEC exam board and I did 15 GCSEs overall, straight A*s.
It really depends how much workload you feel you can manage. RE did have ethical scenarios which looking back were quite useful but they're the sort of things you'll learn anyway when preparing for interviews and stuff (abortion, euthanasia etc). I don't think you'll have less of a chance getting in if you drop RE. In all honesty RE is probably one of the ones I revised most for just because it is all content you need to know. My paper was structured into 4 units, and each unit had a definition question, 5 mark describe question, 8 mark explain question and then 15 mark essay question. By some miracle I got top in the year but I know that is because I put a lot of work in since I was naturally better in other subjects (RE was required at my school).
I handled the language GCSE pretty well, but that does depend how naturally German comes to you and how much revision you think you'll need. I'd recommend doing 15 mins German duolingo every day. I did this for french and there were so many random words that would pop up through the year that I recognised through duolingo which I think really helped.
Although most med schools may not mind what GCSEs you took, a lot will care about your grades. I'd say it's better to get 11 good grades then 12 mostly good ones with a few lower ones.
If you are to keep RE I'd say make sure you revise early - I'm assuming you'te Year 10? Or 11? Either way I'd say after you do a test in class make notes of that unit and some flashcards - drastically reduces the amount of work you'll have to do later where you can just do lots of recall. Also with RE I found with WJEC there were some key phrases you could use for lots of different reasonings - like I remember using 'free will' a lot and 'Kindness is one of the core values of this religion and so...', but your exam board may have a complete different structure.
It is tricky at the moment to decide. If you have mocks coming up soon maybe you should see how you do overall then and then decide if you'll be able to handle RE - but if you really don't think you'd be able to do that without dropping a good few grades in other subjects then drop it. If it's only like a chance of maybe going from an A to a B in a non science/maths/english then that shouldn't effect you too much.
Sorry if this is long and confusing. I struggled with the workload of 15 but still succeeded, so you can definitely do well with 12 if you work hard. That being said I put a lot of work in and paid a lot of attention in class so it really depends on your capabilities. I hope this helps a bit - may be useful to know what other GCSEs you do? And what unis (if you've thought that far ahead) you're thinking of applying for?