Cooking tends to be a little easier in motorhomes designed for the UK market rather than the continental ones - because UK-spec motorhomes will almost all have an oven and at least 3 gas rings. A lot even come with built-in microwaves. Whereas the continental models tend to have a couple of gas rings and that's about it.
Our last motorhome was British built and had a cooker with an oven, a separate grill, 3 gas rings and one solid electric one and a built in microwave. To be honest I thought this was overkill really so we removed the microwave to extra cupboard space. Our new French-built motorhome only has 3 gas rings and a combination grill/oven (and it only has the oven because it was spec'd for the UK market, the French domestic ones don't have the oven as standard) and although we've not had the chance yet to go on a long trip, I know this will be fine. We do a lot of cooking outside on a gas BBQ
I don't cook complicated meals when we're away on holiday though....grilled meats, baked camembert, pasta, roast potatoes, curry, stir fried veg, things like that are perfectly easily do-able.
I've never really experienced that on campsites.....in general people are friendly and will call out good morning or wish you bon appetit if they walk past, but its fairly rare for there to be full-on socialising between strangers. Though we do tend to avoid the large holiday park type sites if we can - they're probably great for families with kids, but we prefer something smaller and quieter.
When we use campsites we use them exactly as we would a hotel.....have breakfast and decide on plans for the day, go out to visit somewhere/do some shopping, come back and chill with an apero, cook dinner or go out for dinner in the evening. And from what I've seen of other campers they mostly do the same. Not many people spend all day every day on site.