Pretty fair analysis all-round.

I'd add in the guaranteed soft-landing via silver - which isn't relevant to you if you always make silver - and the better treatment in IRROPS, which definitely is the case but which is hard to quantify.

Not sure, but I think there are some seats you can reserve as a gold that aren't open to silvers which aren't exit rows?

I think there's a slightly more generous luggage rule too, but I can't remember the detail. Edit: details here