From this account, there are far too many issues involved to address each -- and it would be helpful to know the state.
Also, be aware I cannot give legal advice in this forum -- I merely speak with respect to general legal principals give the circumstances you mentioned.
The resolutions to many of the issues you mention depend entirely on the actual documents: the condo deed, the document of trust, Father's will. Also, the exact relationship and legal status of the siblings, whether these siblings were "guardians" or "trustees" of the trust fund.
In whose name is ***** ***** to the condo? Friend's Father bought the condo and "gave" it to Friend for life, but did Father transfer the deed to Friend's name?
If so, the condo belongs to Friend, and Friend has full ownership and control, and right to dispose (sell or mortgage it) of it.
If the Father retained the deed in his (Father's) own name, without transferring deed to his son (Friend) or others, then it was part of Father's estate when he died and should have been disposed of by father's will or by rules of intestacy.
However, if Father's will contained a legacy of a "life interest" to his son in the condo, then Friend has an absolute right of possession to the condo for the duration of his life, and no matter who owns the remainder of the condo property rights (siblings?).
If Friend does indeed own a life interest in the condo, then Siblings would have NO control or right in possession and can be excluded though legal means (and liable for damages to property).
If Father transferred the deed to Siblings "50-50," then the condo is THEIR property to control absolutely, UNLESS the deed of transfer included the language conveying a life interest in the condo to Friend.
If Father transferred the condo deed into this "Trust Fund" for Friend, then the trust fund trustees (siblings) own the condo but must manage it for the exclusive benefit of Friend, who is the beneficiary of the trust. There are legal means to force them to do this, or ask the court to remove the siblings as trustees and appoint new trustees.
If Father deeded the condo to siblings "50-50" they own it and can do with it what they wish -- including evict the Friend, or charge rent, or anything -- UNLESS the deed of transfer included a clause granting a "life interest" in the condo to Friend. [Various aspects of property can be transferred the the deed to different parties: for example, Father could have transferred ownership of the condo to the siblings entirely, or with the condition that Friend retains a life interest, and so that sibling are entitled to possession only after Friend's death.
NOTE: So property rights to the condo depend entirely on the deed of transfer and REGARDLESS of Father's intentions or earlier statements to Friend.
The Trust Fund:
If the trust fund was created orally, the existence of a trust and it's terms will have to be proven in court.
If the trust was created through a written document, the terms control, and the court will enforce them. Friend can ask the court to force the trustees to comply with the terms of the trust. He can also ask the court to REMOVE THE SIBLINGS AS TRUSTEES and appoint new trustee.
If the siblings, as trustees failed to do as the trust terms dictated, and have been taking money out improperly, they can be taken to court and forced to restore ALL THE MONEY THEY WRONGFULLY REMOVED for themselves.
Also, any "legal documents" such as deeds of transfer, powers of attorney, etc., that Friend signed while he was an invalid, and signed only under force from his brother -- "undue influence" -- may be nullified and values recovered:
Beyond that, additional wrongdoing by the siblings may be redressed though legal actions against the siblings for fraud.
If I can be of more personal service contact me directly via skype, e-mail available at rscottakin(dot)com or from LinkedIn or the directory at the State Bar of California.