A riot might lower your order more than expected, so you want some buffer, but it's really dependent on how comfortable you are with risk. Also, you can delay buying one of those edicts that gives a big +order bonus, so that you can do it in an emergency.
Initially it's to lower cock desire and to make prisoners angry (which makes them easier to hit, but also more likely to attack and use special abilities). If you get too slutty and use it too much, the effect basically reverses.
They will likely throw you on the table if your cock desire is high enough to initiate a handjob. Keep your cock desire low to avoid it, unless you don't want to avoid it.
If you want to keep working and earning tips until the end of your shift, you don't want it to happen. Once on the table you can drink beer/cum for tips, and get tips as the prisoners ejaculate, but it's not as much as if you served them drinks.
Which stats are those?
To (eventually) unlock sex skills, like handjob, you have to keep doing the sex activity, but that doesn't necessarily mean losing. As long as you don't run out of Energy (look into Healing Thoughts), you don't lose the fight.
To increase stats like Energy and Charm, you have to do things that give Energy or Charm exp, which for Energy usually means using skills that use Energy or orgasming. For Charm, it's most easily gained by letting prisoners jerk themselves off.