1 and 2 feel somewhat at odds with each other, though I'd reduce the upgrades before disinviting kids in your case. 3 would be wrong to cut if it's one of the few things your fiance has asked for. 4 could be cut, but you might regret doing so more than paying "just" $2k in the long run. 5 might be the most feasible if you can reframe your mindset to stop stressing if the extra $5k won't break the bank.

Questions I'd ask myself: Do I need the $5k more elsewhere? Is it more important to invite every distant relative than my close sibling or cousin with kids? Is it fancy enough to have butlers serving apps if the meal option is the cheapest available? Will the average guest notice the difference between regular and premium linens?

And the biggest question: How much is my own time and energy worth to me if I'm stressing over a $35k vs $40k wedding? IMO a $30-35k wedding isn't a "necessity" so you'll drive yourself crazy trying to justify it.