On a Mac, e.g Mini, some newbie questions

My dream machine at this time is a Mac Mini, such as the M4 based Mini which has just been launched.

Questions, cos I have been a strictly PC user for about 3o+ years., and never used a Mac.

1. If I buy a Mac with limited data storage, such as the one with 256GB SSD, can I expand the effective storage for software (DAW and plugins and tools) by installing these on an external external SSD, which would provide a more cost effective way to expand the storage. Buying the 1TB on board SSD from Apple, will set me back and additional £400 over the base config of 256GB SSD, when I can get a 1 TB external USB drive for about £80 or less.

I know that the on-board SSD from Apple will be much faster, but I do not need blazing fast software loading times. Most of the time, when my DAW loads, I expect that loading event to occur no more than once a day, or sometimes I may keep my DAW running for as long as a month, working on the same project. So the loading speed is kind of not of significant importance. Any old SSD with at least 500 Megabits/second transfer speed, should be more than fast enough for me.

As stated above this would save me about £320.

2. Does the Mac Mini - "hibernate" so I can put it to sleep and wake it up, with all my software that's running, still loaded in RAM. Or is this hibernation feature, only possible on a Mac notebook?.

3. How best can I use the existing monitor I have which has a DVI port, with the new M4 Mini, which has Thunderbolt 4 and USB C ports, and HDMI, any way to convert video to DVI from Thunderbolt 4, USB C or HDMI?

Link to M4 Mini is below

https://www.apple.com/uk/shop/buy-ma...b-memory-256gb