When I’m given free stuff I tip as if I paid for it. So if part of a meal is comped, for example, I’ll use the original subtotal, pre-discount, to figure out what to tip.
If I’m only getting drinks (coffee, alcohol etc.) I default to a $1 tip per drink, and if given a free drink I’ll add on to that while factoring the cost of what I’m given. But if any food is involved I start at 20% on the subtotal, then round up or down to the nearest 50¢ or $1 depending on how long I stay at the establishment and how much the subtotal is.
For takeout, I’ll tip less since I’m spending much less time in the establishment; I might round the total up to the nearest $5 or $10 depending on how much I spend.
And for delivery, I have basically never ordered for delivery in my entire adult life, and don’t plan to, I’d rather just go and pick up whatever I order. I was a pizza delivery driver before UberEats and the like were common and quickly got a feel for that etiquette (people were usually pretty generous) and decided it was a luxury I could live without.
Compared to you I guess I’m a bit cheap but I’d still tip the same even if front-of-house people were making more money, unless they explicitly tell me not to tip them (which has happened before). I don’t think people should feel bullied into tipping, because I think the business should be paying them the living wage instead, but just like at any other job good performance should always be rewarded.
Spinach and extra cheese are already ubiquitous toppings for pizza so now that you mention it I’m a little surprised palak paneer hasn’t taken off. I can see it happening in Rhode Island, where there’s both a lot of Italian and Indian cuisine.