In the trade window, there is an 'Identify Item' (magnifying glass) button at the bottom, to the right of the trade button (checkmark) and repair button (hammer). After clicking the button, the cursor changes to an identifying glass, and you can click on unidentified items in the character's inventory list to get a conformation window stating the cost of doing so.
The Lone Wolf talent gives some bonuses to a main character, but reduces the maximum party size by one. If both characters take that talent, you can not recruit any companions or henchmen. One of the bonuses is an extra ability point when levelling, but it is not retroactive, so this talent is best taken at character creation.
When companions join the party, if they have less experience than the main character that asks them to join/rejoin, they get an experience boost to match. Henchmen only gain experience when they are in the party, and don't get a boost when they join/rejoin.
The 'Filter Completed' checkbox removes quests that are done (solid black diamond).
There are quests with requirements to complete, or that need access to particular areas, etc, but other than that there is no particular order. It is possible for a main plot quest to make certain side quests unavailable (ie triggering combat with an entire town will block side quests that may have been open), or killing an NPC can block side quests.
There is one gate with no actual gate, and no check on level or party size, which is the easiest gate to leave by (suitable for level 3 or 4). If you explore in town enough, you can find an area with combat sutable for level 2 or 3.
Paintings are worth a lot; sell them, or trade them for skill books, etc. Cups and pillows can be crafted with, plates sold, knives crafted into daggers (which scale to your level, so even paper/gold knives are useful). Type stuff into the crafting table (link above) to see if there is something that can be done with it.
