The first question is "What the fuck is the tail for?"
As much as evolution doesn't fit into fantasy much, nevertheless a good 80% of the bestiary will contain creatures that either directly come from real life, or are similar to them in some way that might make evolutionary sense.
A biped with a tail works with monkeys because it's a counterbalance and helps when living in trees. But if said tailed biped is a plains walker (like a Human) then that tail is completely useless - with the exception of it being naturally selected by females due to being considered attractive (see peacocks).
>tail holes in clothes?
Not exactly a major issue here. No need for a hole, you just hike up your trousers/skirt up to below the base of the tail.
>tail grooming?
If you are not a social creature, reaching it is not really an issue. It wouldn't be much different from cleaning your feet or hair. If you are a social you may find yourself getting help/and helping a relative, friend, or partner with it during a bonding exercise.
>sitting?
Sitting isn't an issue either, as the tail would likely protrude further up above the rump and therefore not get in the way at all. And it could probably easily turn to the side in case you rest against a flat surface.
>combat?
The primary striking areas in combat are the eyes, head, neck, and throat. Anything else is only a valid target if you are a pack hunter who relies on number to take out your target. The tail may serve as a useful counterbalance that allows for more acrobatic forms of combat, and therefore is actually more of a boon than a hindrance.
Besides, anyone trying to attack your tail is just setting themselves up for being killed quickly, as they've have to expose their vitals to do so. So... that's also a good thing for your if you had the tail.
Well there's that too. If the tail existed as a partial justification for their females having massive tiddies, I wouldn't complain.