Just checked Ultimate Wizardry Archives...
1. Well, main doc is first 60 pages or so. First 4 games, according this manual, using exactly the same system, so only flavor and installing info remained.
2. Spells are here, at the end of first part manual.
3. Potions are exactly the same as "instant spells". If you have it identified, it will be exactly the same (and you need manual to know what it does with all this SOTA and DEGA abbreviations).
4. You need to identify most of loot to use it (it's in the first manual too
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No, I didn't play game by myself, but it's look quite logical for me...