> 4 - not having swap seems to make some things not work too well
Swap depends on how much memory you have and how much memory your programs need.
Back in the day when ram was less than a gig we would use 2 to 3 times the ram size for swap. You would add up the number and size of your programs you needed to run and give it that extra swap knowing that when swapping started it would slow things down some.
Nowadays you can have 32, 64, 128gb and more ram.
Programs are also bigger, but you still figure how much memory the programs take and add them all up and compare that with your actual ram.
If you have 32gb of ram and only read mail and only browse google and PLUG, then you wouldn't really need any swap. But if you keep hundreds of tabs open, and have a huge memory resident database, and edit images and video, you may want to have swap.
If you have 4-8gb of ram I would think 3 to 4 times that for swap.
16gb ram 1 to 2 times swap.
32 or more 1 times, depending on what you're doing maybe more.