The court will determine your financial obligation. After that, you are not obligated to your ex and you are not responsible for her decisions. You can hope for the best for her but it's up to her.
We can't emphasize this enough. Court will do what it does. Solicitors will do what they do. Your challenge will be to balance yourself between two perspectives.
On the one hand you will likely feel an emotional pressure or need to "gift away" more financially than you should. (After all, any resources you are able to protect
now could be judiciously used
later to wisely aid her here and there.
On the other hand, you will need to work on yourself, to recover from nearly 30 years of chaos and discord, to Let Go and Move On.
1) Does alimony increase for someone that has BPD / Mental Illness?
We aren't professionals here, but I would not expect alimony to increase but the length of alimony might lengthen. As I mentioned before in my own experience, courts want the lawyers to reach agreement on many of these details. That is where you can exert your influence over the outcome so it is less unfair to you but better for your ex-spouse regardless how she may sabotage herself.
2) How can that money be managed?
Pondering your situation... beware of feeling you have to be "overly fair". The court and her solicitor will ensure her outcome, you on the other hand have to protect yourself. Real fairness is not a great concern to the court. It is more concerned about laws, rules, policies and procedures.
Perhaps alimony will protect her from quickly wasting her money. It will be a regular source for her over however long it lasts. What will be more difficult to measure out will be items which usually are ordered as lump sums, and seldom parceled out in increments, such as her equity in properties, savings (minus debts), retirement accounts, etc. Ask your lawyer how such things can be negotiated to protect her from wasteful binges.
By the way, you did well to take her cards. If these credit cards are joint accounts, close them now so you limit what damage she can do.