The "Retry" section of the Spellcraft skill description helps you out here:-
When using detect magic or identify to learn the properties of magic items, you can only attempt to ascertain the properties of an individual item once per day.Similarly for Appraise:-
Additional attempts to Appraise an item reveal the same result.
Thus, for both these skills, you can't take 20 (or it has no effect). You can take 10, if you aren't threatened or otherwise distracted, but you only get one chance at it per day, and success is not guaranteed.
As for smashing open doors, and other objects, that's fine. The question is whether there will be any consequences for those actions. Any creatures nearby will certainly hear the racket, and may well react by investigating, or preparing for a fight. Furthermore, if the door belongs to someone, they may not be too happy with it being smashed in!
As far as I can tell, anymore most people will allow the party to ‘take 20’ on the spellcraft check to identify a magic item (though it requires detect magic spell) on the appraise check to value an item as long as they are not doing it during a time crunch situation. If in the middle of the fight you want to grab a staff off the recent corpse and use it during the fight you will have to cast a detect magic and make a single roll (even then I was thinking it still take 3 rounds, but I’m not sure of that).
So there is rarely any mystery in what something can do or is worth.
However, some groups do try to keep that mystery alive. You get one roll for a spellcraft or appraise. You can’t attempt again until your skill increases (either from additional ranks at level increase or something that increases your intelligence). I wish my group did that, but they are not receptive to the idea.
Also for doors that are stuck or when they want to break it down they will just sit there and pound on it. I don't know what they are going to do when we run into a locked object.
Give them a locked chest full of potions. After they sledge hammer it open tell them it is full of damp glass shards and what used to be a magical liquids is draining out through the cracks in the bottom of the chest. Then they will realize it might be worth while to look for a key, prepare a spell, or take ranks in a skill that might be useful in those situations.
If they are clever and gently jiggle it to hear the clinking, then wait until the can open it without damage. reward their clever behavior with several useful (but not overpowering) potions appropriate to their level.
- identifying objects is 1 try per day per person with detect magic!
but to be honest, our group has 2-3 people with detect magic and at least one of us always manages to id the object
- stuck doors and containers... be aware that pounding on these makes noise... usually a lot of noise, especially in stony undergrounds, which can echo quite far... when they get that door open they might find a well set ambush right behind it with enemies ready to take that group down as soon as the group breaks the door: surprise round for the enemy! Also that enemy will already be full buffed etc... this can often turn out to be a near TPK. Pounding on a locked container can damage whatever is within... especially things made of glass like potions, if those potions are bottled fireballs the entire container might explode in their face (read the rules about saving throws for unattended magic items: rings, amulets, ... they all can break!)
But the biggest question is: are they having fun doing it this way? And will they still have as much fun if forced to be more roguish/stealthy? This game about fun: if it ain't fun, it ain't right!
Also, there has to be something about the item that would give clues to what it does for them to identify it. As in you can tell the sword is enchanted becuase of the detect magic, but without some type of hallmarking by the creator knowing how much is impossible. Same thing if the wand was built using the concepts portrayed in the magic items listing sure the skill could help identify it. However if the maker made a plain or non-standard version of it, then no the skill doesn't help. So sometimes they quickly identify items, and other times they have to use the old trial method.