It depends on how the deed reads. If it says "Father and Son as joint tenants with the right of survivorship" then son automatically receives it. If it says something else or says nothing, then a probate is necessary. I recommend you have an attorney look at the title to determine whether you own all of it or not. You have my sympathy for the loss of your father.
I am assuming that since the estate is in probate there is an attorney. That attorney should be addressing the situation of your brother tearing up the property. One owner can force the sale of property. If you are an owner and want to do that you need a lawyer to file a partition action. A partition action will force the sale of the property. In my 21 years of practice I have all kinds of real estate litigation. They get you the result you are requesting; however, the time they take and...
Your mother can leave her estate to anyone she wants, even non-relatives. Be sure she goes to an attorney so that her will is pepared and signed correctly. Your sister can always complain that things aren't the way she wants them, but so long as your mother's will is done correctly your sister's success in contesting a will under the circumstances you describe is about zero.
You certainly have a right to know how much your treatment will cost. It is not unusual that a chiropractor will have you sign an assignment so they can direct bill your insurance company. There are many doctors, not just chiropractors, who want to bill out that $10,000 in PIP you have as quickly as possible.