In Florida, you may disinherit your children or any other relatives.There is an exception when it comes to a spouse. If you wish to disinherit your spouse (and you do not have a prenuptial agreement) your spouse will receive an elective share--30% of your estate.
Language must be placed in the will to clearly show your intent. State exactly who you wish to receive and who you wish not to receive from your estate.
Without an estate plan-- you are allowing someone else to decide what happens with your hard earned assets.See question
If you do not feel comfortable with the 1st attorney you met with, meet with another one. If you do get a 2nd opinion, it might be best to get that prior to hiring an attorney. Don't rush to hire an attorney that you do not feel comfortable working with. After all, the issue being dealt with is yours.See question
I am sorry to hear about your situation. Parents can typically have control over their adult children's medical and financial decisions if there was a Durable Power of Attorney in place. However, the POA must be signed when the client has the capacity to know what they are signing. The mental state of a drug user would be questionable. Unfortunately, you would have to proceed with a guardianship through the court system.See question