We tried vanilla Decent and we all liked it, we did not finish the first quest (ran out of time), then the next time we played the game we jumped directly to the 2 quest and got annihilated by the boss. So my question is, are you supposed to keep the same heroes and items you find from the previous quest because the boss was just too strong for us or is every quest a "new" game?
Every quest is a new game. You can keep the same heroes if you want to, but all gear, training and extra skills are discarded and you start fresh in the next quest.
Second question (Mandatory idiot question) : We can't figure out what the pet does. How does he (or she) move? Can the OL kill him (or her)? what about respawn? Traps?
Familiars are invincible and they move after the hero who owns them has finished his turn. Each familiar (or companion) has a special ability detailed in the rulebook. Most traps trigger off of things that "figures" do, and familiars are not figures, they're tokens, so generally they are immune to traps. Even if they do somehow get caught in one, they can't take damage.
Third question : When a Hero enters the town does he regain full health and fatigue tokens?
Only if he re-enters town by dying. =P
Fourth question : Hero order tokens... I understand run, attack and advance but i'm not so sure about the ready command...
Ready allows you to place an Order token (one of Aim, Dodge, Guard or Rest) and either move your Speed OR make an attack. You may place the order before or after doing the other part of your turn.
Aim lets you re-roll one attack you make (any or all dice therein.) It remains on your hero until it used, until your hero moves (voluntarily or otherwise), or until your hero takes a wound.
Dodge lets you re-roll ANY attack that targets you (only once) in the same way as above. The new roll stands for ALL targets of that attack. Dodge stays until your next turn.
Guard lets you make an attack roll during the Overlord's turn (only) as an interrupt effect. You can interrupt in between any two events, such as moving from one space to another or immediately before an attack is made. You cannot interrupt in the middle of an attack (ie: after targets are declared but before dice are rolled.) Guard stays until your next turn or until you take a wound, or until it is used.
Rest restores all of your Fatigue points, up to your maximum at the start of your next turn. It stays on you until the start of your next turn or until you take a wound.