If humans have flaws then they are imperfect beings. Humans have flaws. Therefore they are imperfect beings.
Valid, although ambiguous in quantifiers. This could be fallacious if the inconsistent quantifiers are added. Two examples of consistent insertion of quantifiers would be "If a human has a flaw, then that human is an imperfect being. Some humans have flaws. Therefore those humans are imperfect beings." and "If all humans have flaws, then all humans are imperfect beings. All humans have flaws. Therefore all humans are imperfect beings." An example of inconsistent quantifiers would be "If a human has a flaw, then that human is an imperfect being. Some humans have flaws. Therefore all humans are imperfect beings."
Either humans are perfect or they have flaws. Humans aren’t perfect. Therefore they have flaws.
Also valid, with the above caveat.
Either beauty is objective or subjective. Beauty is not the same for everyone. Therefore beauty is determined by personal opinion.
Invalid. The first sentence introduces a claim that isn't used at all. The second sentence is presented as if it proves the third, but it doesn't. The second sentence eliminates one possibility (beauty is determined by something constant across all humans), but one cannot conclude, just because one possibility has been eliminated, that a second possibility must be the case. That is implicitly a false dilemma.
If laws achieve order then laws benefit society. Laws provide order. Therefore laws benefit society.
Has the quantifier issue mentioned before, and switches form "achieve" to "provide". Other than that, valid. The quantifier issue is more of a red flag here than in the previous argument; I can easily see someone arguing "Laws provide order, X is a law, therefore X provides order", which is fallacious if "Laws provide order" is a statement about laws in general, and not all laws. That is, it's possible for one law to not provide order, but it to still be the case that the total effect of all laws taken together is to provide order, just as it's possible for the total amount of work done by a team to be positive, even if one team member doesn't do anything. Another issue is the ambiguity of "benefit". "Benefit" can mean "provide something positive", or it can mean "has a net effect that is positive". So if a law has one effect that is positive, but another effect that is negative and of larger magnitude, the law would satisfy the first definition but not the second.
As for whether the arguments are sound, that has an element of opinion, and depends largely on how you're defining your terms.
