Yeah, that sounds bad. If you create a Super League the playing field should be even. Giving some 100ME and others 350ME sounds like creating the same problems we are facing right now on a bigger scale. FFP/salary cap/transfer restrictions need to be on point (which is the biggest chance of all of this).
Sure, but clubs like Barca, RM and United will also bring back more money than likes of Tottenham (who I suppose is one of the teams in that level 3) or invited teams from level 4. Probably not 3,5x more but still. From my egoistic Barca view I'm all for us getting more money than (some) EPL clubs. F*** them.
Times of equality and "morale" in football were long gone even before all of this happened. And if Barca wants to survive (and not only in current situation, we wouldn't stay out of this league because of "higher morale standards" or other reasons even if our finances would be better simply because we can't afford to stay behind our direct competitors RM/AM and other clubs who would get money from ESL) and remain one of the top teams it's what we have to do, like it or not.
Also, we'll have to wait and see how exactly prize money will be distributed but from what I've read a winner of ESL will apparently get 400m. It doesn't mean one of the clubs who are now in lower levels and will get less money for participation can't in the end win ESL and potentially get more money overall than us (if we won't get results) for example. These are all teams who already have big resources and good squads so potentially anyone can win. Some are more likely than others but it's not like you'd give Levante or Getafe 100m (which would obviously save them for years but wouldn't be enough to make them competitive longterm against these teams) and say to them "now you have a chance to win another 400m if you beat all these clubs who were already in a much better starting positon than you".
I agree with your point about Salary cap restrictions.