I started off spreading stat points out relatively evenly, for the first 3 or 4 levels. The next 3 or 4 I tried to concentrate more on Strength and to a lesser extent on Dexterity, but it varied based on bonuses on equipment that I upgraded to, or requirements on new stuff. Around level 8 to 10 I had more melee and ranged resistance than magic, and started to run into more mages, so boosted Intelligence some more. Playing again I'd probably only put a few points into Intelligence, and see if I could get by with being more vulnerable to magical damage (temporary boost potions are an option for tough fights, or equipment enchantments could help with resistances).
After going up a few levels, I started leaving a few spare stat points (unless I figured I needed them somewhere specific), so if I ran into problems, or found some equipment with stat requirements I didn't meet, etc, I would be able to adapt more easily. Sometimes it was just a case of not knowing where they could be best applied, so leaving them until later to decide.
Once I got into the high 20s for level, I didn't really need to apply any stat points. There were still challenging opponents and areas, but nothing terribly difficult, where I needed to burn through healing potions or kept dying. Leaving the stat points unused made sure the game didn't get too easy.
With locked chests, the contents are determined when the chest is opened. For merchants, unlocked chests, mineral veins, etc, the contents are determined when you get close enough and run the crosshairs over them (merchant inventories get reset each time you level). If you disable the option to show crosshairs, inventories can be determined when you are still a fair distance away.
If you save before the contents are set, you can check the inventory and reload if there is nothing of value. I wouldn't waste a lot of time reloading, though, especially since the game seems to keep track of how long it has been since you last loaded the game, and tends to give you better loot if you don't reload. Due to the random item generation, though, you can get better loot sometimes if you try a few times, which can come in handy for chests that always give a good quality item or boss type opponents that always drop something when defeated (save just before finishing them off), etc.
Reloading can be useful at the start of the game to get equipped, and I reloaded to make sure I got at least a couple malachite gems out of each malachite vein (3 are not too difficult to get, 4 are possible, but pretty rare). Malachite gems are required for all level 10 enchantments (I mostly stuck to level 9, since they have almost the same effect but use common ingredients), and for any healing aura on jewelry (so I only used level 10 healing auras, being lucky enough to find that enchantment formula in the Broken Valley enchanter's cellar, with a bit of reloading).
If you skipped Dae's comments in the spoiler tag, you don't really need to; there is just a mention that there are a couple confined spaces in the game where pure ranger tactics may not be the best approach.
