I agree with a lot of what you say, but I've had to pick this line out, because unfortunately, the short term is MASSIVELY IMPORTANT, now more more so than ever.
If we drop out of the Premier League, with zero crowds, we are falling into a financial abyss. I honestly don't know how long EFL clubs can carry on under this current crisis, nobody does. PL clubs are at least still being propped up by the billions in broadcasting rights, there is still always going to be a TV product to sell to the masses, crowds or no crowds. But nobody pays to watch QPR v Barnsley, and if we we end up plunged into that market, then we are bang. in. trouble. With the rest of them.
So whilst a long term plan is all well and dandy, and not something we should lose sight of, the short term - the here and now - is more crucial than its EVER been before. Pre-Covid, relegation from the PL would probably not have been a catastrophe for BHA. Now though ?
While I understand your concern, the value of the squad has skyrocketed over the last year. Lets compare with i.e. Burnley, WBA and Fulham, if they get relegated, what are they able to sell to mitigate the drop in income? Brighton could just sell two or so of the great talents and a few more established players and then, with the parachute money, the club would be fine economically speaking.
Adding players on PL wages means you could be stuck with another Locadia or similar for plenty of years. There is no guarantee that a signing are going to be a success, if you are not 90% certain that you've signed the right player then you are taking a great risk at this time.
Currently its quite obvious that - even if some fans disagree - the club is pretty happy with the squad.
All of the "Murray left and now we only have two strikers and its all doom and gloom" is just overdramatisation. Do people actually believe that Trossard would be a worse CF than Murray in 2020? Even Ali J got a great nose for goal.
The future is great, pretty much whatever happens, and the present is good as well. A lot of names mentioned over this window, like Wilson, King, Pukki, Deeney etc would most likely add very little to this squad. There is plenty of ways to work around this alleged lack of strikers, since there is a lot of quality in the squad overall.
It's going to be fine. I'm sure that in a few games time people are going to realise that the team is good enough to relatively comfortably stay up and hopefully a bit more than that.