Latin GCSE

Personally, I really enjoyed doing Latin at GCSE; I thought it was a mixture of other subjects in an interesting way- analysing words from english and class civ (i think class civ is similar, but not too sure as I didn't do it). In response to your question, I think it is definitely viable with your other options, and you should have no issue. However, there is some memorisation required with regards to the vocab, grammar, and the set text. The vocab and grammar are fairly simple, although the grammar may take some practice. The set text, despite its length, is probably what you will be spending a lot of your final year doing (maybe earlier, but can only talk about my experience), but does still require time outside school to learn the annotations and the translation. I don't think there is too much of an issue when you do Latin in combination with other subjects as you will be tested on the set text, vocab, and grammar many times throughout the course- after you learn the set text once or twice properly, it comes back very quickly around exam time. I don't know what your set text will be as it changes.

In conclusion, I think you should go for it if you enjoy the subject. Hopefully, you found something helpful in my rather long and verbose response- I apologise for that.