Interesting discussion,

DQ was written by wargamers, who I guess wanted to be able to simulate heroes from their armies, and hence went to a lot of trouble to provide many weapon choices.

They were also influenced by various fictional books, as evidenced by their colleges.

As I saw it, armies did not interact with mundane things during a battle, and so things like cutting down trees to make a pontoon bridge (Caesar at the Rhine) were not included in the rules.

There is always the question of scale.

There was a comment that spells were meant for human sized targets.

So a door should be one target.

Here is my take:

An inanimate object wont have FT, so all damage goes straight to EN.

I would assign EN on a pro-rata weight, say 1 EN per 15 lb.

You can say that some have natural EN armour, such as bark or iron strapping.

That will work for any weapon or spell that does damage.

It also works for non-weapon damage such as a pry bars, saws etc – no chance of failure, so say D10 +1 point of damage  per 5 full points of Strength per pulse or minute.

As to actual time and effort, I am sorry, to me this is just a game.

The role of a GM is to facilitate the players having fun by giving them opportunities to show off the prowess (competencies) of their PCs.

So the question really is – what is the PC trying to achieve?
Open the box, show off their muscles to the comely wench who is watching, get at the weapon that will save them against the ravening horde that approaches??

In which case, assign a difficulty rating (0.5 to 5) where low is harder to achieve, and assign to a STAT EG STR.

The ask them to do a characteristic check (roll under difficulty * Characteristic to succeed). The higher their roll (assuming success), the closer to doom they got (the wench is looking bored by the time you prise the box apart).

Best, Ian