ITunes Match - can it be an iTunes Sync workaround - if so do I need iCloud storage as well?

[Steve1955]

MacBook Pro [2009] 500Gb El Capitan 10.11.6 [no higher updates available] - iTunes 12.8.2.3 [no higher updates available] - contains 270Gb of music downloads from Apple, Amazon, original recordings of father and brothers bands, CD rips etc but no dodgy torrent rips or the like. All tracks play properly in iTunes and other media players.

iPad Pro 12.9inch (4th Generation) 1TB iPadOS 14.0 - latest version of iTunes or I think its now called Music

iPad Air 2 128Gb iPadOS 14.0 - latest version of iTunes/Music [don’t know if there is a version number]

iPhone 6S Plus 128Gb iOS 14.0 - latest version of iTunes/Music

1. iTunes on the MacBook is unstable [I’m working with Apple senior tech support] and I am only able to sync 500MB of music from the MacBook to the iPads - I have 270Gb of music on the MacBook.
2. I am looking for an iTunes Sync workaround to get the full 270Gb of music on to my new iPad [hence buying the 1TB version] and 100Gb onto each of the the older iPad and iPhone, without using iTunes Sync.
3. I want the tracks to reside on each device in order to be able to play music without WiFi or cellular coverage e.g. skiing, hiking, sailing etc [so streaming is not an option].
4. I also want the tracks to be playable in iTunes on each device to be able to use iTunes functionality such as shuffle, playlists, album art, track names etc therefore the likes of VLC media player is not really an option.
5. If I buy iTunes Match does it store the music files on each of my separate devices [x2 iPads and iPhone]?
6. If so how does iTunes Match deal with the different storage capacities of the devices I.e. do I get to choose separately which albums are stored on the iPhone and older iPad as you can do with iTunes sync?
7. Do I also need to pay for 270 Gb of iCloud storage long term as well as iTunes Match?
8. OR can I use the 20Gb of iCloud storage I have empty at the moment and do several batches of uploads.
9. OR can I get 500Gb of iCloud storage, use it for a few days, do the upload to the devices and then cancel the iCloud storage?
10. If the files are successfully moved to the devices do I still need to pay for Match [assuming I don’t want to add any more tracks] or if I terminate iTunes Match does access to the tracks get terminated or the tracks get deleted?

Thanks for any help you can give.