Streaming Services - do they do everything?

I’ve been having some brief conversations with a friend at a cursory level, which leave me with the following questions pertaining to which service offers the best fit for me.

1. which service offers the highest resolution for $10/month?
2. which service has the most intuitive interface
3. which service can be accessed via a computer interface - makes downloading into my library easier
4. which service can you download music to play offline
- is there a limit of the number of offline songs
- is the limit a "total number of tracks" or "total" per period of time (quarterly, annually?)
- can the songs be stored on or moved to a NAS drive
5. which streaming service crashes the least

Thanks in advance