Neither are ad hom. The first is no different than saying "you can say that a thousand times and it still won't be true." That is exaggeration for effect, refers to a person's ACTION and not any attribute of the person's personality, character, or anything else about the person personally.
The second statement is an opinion expressed about the post and again refers to an ACTION, and not anything about the person's personality, character, or any other personal attribute. Criticizing a post is not ad hominem unless it includes a personal attribute of the person making it. The "If you can't handle that. . ." line directly referred to the member's comment threatening to leave the thread because his post was criticized.
Antagonistic? Yes. Expressing annoyance? Yes. Ad hominem, no.
Other examples:
'Your statement is racist or your statement is offensive.' Not adhomen.
'You are racist' is ad hominem. 'You hate black people' is ad hominem. 'You don't care if black people are disadvantaged' is ad hominem. 'Republicans can be counted on to say something like that' is ad hominem.
Calling someone a spammer "involves commenting on or against an opponent to undermine him instead of his arguments."
Telling someone they should leave if they don't like being bullied "involves commenting on or against an opponent to undermine him instead of his arguments."
That is YOUR definition, as stated in the OP.
There is a difference between calling somebody a spammer and commenting on or objecting to spamming of a thread.
Telling somebody they should leave if they don't like being bullied may be insensitive and/or rude, but it is in no way ad hominem.
So how is either 'my definition' of ad hominem as stated in the OP?
Objecting to, criticizing, or refuting a person's statement is NOT ad hominem. Making, even by implication, a judgment about the motive, character, personality, intent, background, etc. of the person making the statement IS ad hominem.