The answer is yes, you will experience a sound quality loss but not a volume loss. Basically the more resolution you can keep until the last moment, the better. even if you record in 16 bit, you're still going to create larger than 24bit files when you mix it down. We're not talking about frequency loss here, what your going to notice is that the mixes won't have as much depth and detail. The best bet is to record at the highest bit depth you can, mix in the highest bit depth and dither and print all of your mixes as 24 bit files. This will retain the most depth and detail and the most compatiblity with the mastering house. All mastering houses that I know of can accept 24bit files and this is how you should deliver your mixes. I don't think it matters as much if you use 44.1 or 48k sampling rate. just about all converts oversample so the issues there were about 44.1 verses 48 don't exist anymore. Hope this answers your question.

i agree!

but i do expirience a great loss of overall quality when i convert from 48 to 44..... so i do all my recording + mixing in 44

Yes, if you don't have a good sample rate converter, then you are going to notice a decrease in quality when you convert it, if you are the one doing it. If you are using a mastering house, they usually have a good SRC and this doesn't become an issue.