I can see how some of what you’ve said could be beneficial to some users. There’s been previous discussions about some of this functionality being added to pots like directing certain payments to specific pots.
If your balance is low money will not be moved from your pots automatically (at current) the money is ring fenced, although there has been sneak peaks to schedule regular payments into or out of pots soon.
The ability for rules to be introduced in the future such as “My BT bill comes out of pot X” or if my balance gets below… move money to my card” will be really powerful if these come to the product. I think it’s fairly certain Monzo are looking to implement these in the long term.
Announced yesterday (in this thread) is the ability to create a pot with interest within the next 3 months which will be a nice feature some people have asked for. It will be interesting to see how this is done.
Personally just having multiple accounts doesn’t really look at the issue and try and find a better solution. It’s simply going with the flow because they can. Having multiple main accounts likely has a higher overhead cost to Monzo whereas a much more flexible solution and intelligent system can be developed with rules and small updates to the pots feature. I also wonder if having multiple accounts would defeat the point of the summary screen as the spending information may not be pulled together to see what goes where, all points that need to be discussed.
I think what’s also important to remember that pots or many Monzo features are only at the beginning on their potential. With more being added to improve them over time. Monzo tend to develop a miniamal viable feature/product at first and use feedback to consistently iterate and improve over time. That’s one of the reasons I like the service so much, improvements never stop.
I can see a lot of potential for pots to cover a large area of what you require in the future. 
That’s just my view anyway 