New r-Pi-4 based LMS via USB SSD - recommended partitions

I've got myself a new rPi-4 and a 2TB SSD (Samsung T7) connected via USB3 to act as a media server on wich I intend to install LMS, Plex and Transmission (I prototyped all these on an SD-Card first so know the process). I've set up the SSD with a new Raspbian image and it boots up fine from USB. The partitions look like this:



Before I start adding LMS, etc, does this look reasonable to any Pi experts out there? I'm new to Linux and not sure what the boot partition actually is and whether 256MB is going to be enough for my intended use-case. I originally created the image on the SSD via Imager downloaded from https://raspberrypi.org/software/ from a windows machine - it didn't give me any option to set the boot size - can that be changed now or later if needed?

Also what about a swap partition?

NB. I mentioned that I prototyped the entire setup on an SD card first (set up via Noobs). I know I have the option of using the SD Card Copy utility to copy this to my SSD, but I'm a bit concerned about the multiple partitions that SD card has:

Should I be concerned about basing my SSD on a copy of this structure? What do all those partitions mean?

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