yes trust is a legal entity and can sue and can be sued in the court.
nope its not compulsory to all trutee to impledge for suit for eviction,they can authorize anyone of them by giving special power
yes a suit pleaded gainst trust means its suit against all trustees but depends upon the by laws of the trust if all powers reside in only one person or trustee then he is liable for that
yes trustee can be sued anytime when the matter came to light whether he is trustee or not in case of any omission he commiteed during his tenure
anish thakur hc shimla