I can give you the Italian answer - first of all, normally we don't use tomato paste to make sauce, but rather to add a tomato "kick" to recipes. Tomato paste is simply tomato puree that has been cooked down to a high degree of concentration.
A basic tomato sauce is made by
- making a soffritto with onion, carrot and celery (plus other flavors)
- adding tomato puree, or "pelati", more rarely fresh tomato
- cooking the sauce down until the taste and thickness is what you want
If you want to use paste instead of puree, the third step has to be omitted or greatly reduced in duration. Keep in mind that tomato paste has its own taste, and that taste will remain in the final sauce.
It doesn't look like it'd make much difference to that recipe. The juice goes in right after the tomatoes, so it's not like they cook on their own significantly. The one thing you get out of adding the tomatoes first is a way to get them spread evenly around the pan without having to stir, so they're mostly on top of the onions and get gentler heat at first. But you'll be stirring soon anyway, so just dumping it all in wouldn't make much difference at all.
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Here's another question where I mention salting, which doesn't seem to be included in the links you've mentioned Keeping scrambled eggs with tomatoes from being too watery. I like salting in any application where you want to keep that "fresh" flavor and texture but want less water. Of course it removes juice, but isn't that the point?
EDIT: So the "pros" of salting would primarily be the maximum reduction of moisture without losing the flavor and texture of fresh, raw tomatoes (if that's what you'd like to accomplish). The cons would be the loss of juice (although I find it hard to think of that being a "con" when reduction of moisture is a goal) and of course excessive saltiness if that particular issue is troublesome. The use of kosher or other coarse salt instead of table salt ameliorates that particular issue to a point, coarse salt can be more easily brushed off than table salt. .