Hi,
It doesnt matter if they are home recordings or comercial ones. If your music will be played on a CD (44.1 khz) best options are recording in 44.1 or 88.2.

If using video codecs or perhaps wave files instead of *.mp3 then 48000 or 96000 because WMP (windows media player) can handle 16-bit 48000kHz files or else the normal 44.1 16-bit files. If recording out of the outputs (left and right channels) for a audio recording than no, your audio interface (Fireface UC) handle that incoming signal, and recording MIDI is done through the midi input. If more than 2 connections in are needed then I guess you can go to ad-da converters or the input of another audio/interface of which RME has some for that and hook up SPDIF or ADAT whatever optical in also.

Hello
Take into account that a good resolution is important as well. So if you are going to record an event use 24Bit or 32Bit instead of 16Bit.
You get good recording datas with 44,1 kHz/24Bit for producing a CD.
Further you need to know that most of the DAWs calculate effects within a project with 32 Bit (happens when you add some reverb or other effects within your recording project).
That means: It makes sense to work internally of a DAW with 24Bit or 32Bit even if the starting point are 16Bit-files.
So before you export the project to a CD (down to 16Bit) you should use a dither-effect.
Most of the DAWs (such as Cubase, Logic etc.) come with those effects.
One last thing: If you are working with sample rates above 44.1kHz (88,2kHz or 96kHz) you need to have a good converter for down sampling to 44.1kHz. Some of them are so bad that you will lose all the advantages of the higher rate with the converting process. Have a look here: http://src.infinitewave.ca/

All the best
Beat Kaufmann