Thank you for the assistance... erm... why shouldn't I pay the debt before getting kitchen access?
You run into a bug if you do.
In order to progress with Kate, Claire, and a bunch of other quests you will need access to the upper floor of the Drunken Fox. The only way to access the upper floor is to either rent a room or have worked there for the night.
If you pay your debt without having worked even once before, then Thomas will still refuse to rent you a room and claim that you owe him even though the option to pay him has disappeared. You also cannot work there because you have no debt.
EDIT: I realized I didn't say much about combat even though you said you lost at combat a lot.
Combat is composed of rounds. Each round, each member of your party and the enemy party will get a turn. Who goes first is determined partly by who has more agility. Some skills will also change the order during the next round of combat.
It is impossible to act twice in a single round of combat. By that I mean have your MC act, have someone else act, and then have the MC act again all in the same round. You can use skills like Mark Target or Quickshot to do more than one action when it is your turn. Basically, you cannot become fast enough to act twice before the enemy acts no matter how much you raise your agility.
Be careful with the display showing the order of actions when the enemy is stunned. The enemy no longer shows up in the display but it doesn't take into account when the enemy will recover from stun. Stun lasts for 2 rounds; the round that the stun is applied and then the round after that. Once stun wears off, the previously stunned enemy/ally will be the first to act in the next round. If a stunned person is attacked and loses HP, then stun wears off and they will be the last to act in the current round (assuming that they have not already acted). It's still possible for your attacks to miss someone who is stunned. The damage dealt to a stunned person is more than a regular attack but less than a crit. I'd say about twice that of a regular attack.
Mark Target takes energy and TP to use, but it doesn't end your turn. You can also use it multiple times during a turn. It makes arrows do more damage
and lowers defense, so it's useful even if you're not using a bow. It also has the effect of erasing the taunt buff.
