A "harasser" is someone "who makes others feel uncomfortable [by] using words", gestures, and touch.
A "stalker" is someone "who makes others feel uncomfortable" by persistently trying to interact with them, either by using information they thought was private, and/or after they had told the stalker to have no further contact with them.
As Arrowfar suggested, "lowlife" is an offensive term for a poor person who might have criminal intentions.
"Crook" is a mildly offensive term for a criminal. For example, when Richard Nixon said, "I am not a crook", it immediately made many people think he was a "lowlife" and unworthy of being President.
"Mugger" is a factual (but still insulting) term for a criminal who robs people on the street or in alleys by force (or threat of force).
"Thug" is an offensive term for an intimidating, possibly criminal, person. Many bodyguards and muggers are called thugs.
"Rapist" and "child molester" are factual terms for people who commit particular crimes. Because these crimes are so abhorrent (especially to many imprisoned criminals), they are very insulting terms. (Many criminals consider it honorable to harm or kill rapists and child molesters.)
A slang expression for parents who behave in such a way is Helicopter Parents
To quote the Oxford Dictionary definition.
A parent who takes an overprotective or excessive interest in the life of their child or children
As has been suggested it is worth noting this is quite a recent inclusion into usage.
Best Answer
The word "poser" comes to mind.
There are a few words and phrases that generally mean this sort of thing but usually they refer to a specific aspect. Someone who overly values worldly possessions would be "materialistic" but a materialistic person may or may not have the motivation to show off those possessions. They may simply be a hoarder or even secretive about their possessions.
Someone who likes to show off could be "vain", "pretentious" or compensating for insecurities but that may also apply to someone who pulls stunts for attention or someone who tries to "win" every conversation.
"Shallow" is another broad term that encompasses most of what you describe.