On the first point... yes, your status at check-in will be taken into account, so you can't expect lounge access etc.

On the second point... (gifted points), there is officially no recognition of this, however, in the past when giving points to my parents for an anniversary reservation I have called the hotel and asked for them to be treated well (I'm a plat) - they were given lounge access (only did this once btw) so it depends on the circumstances and the individual property, but, in general no - you only get the benefits to which you personally are entitled to.

As an example, even if my wife is staying at a Marriott if the room wasn't in my name or MR# then she would be treated as per a normal guest