I have another question. Alchemists cannot cast from scrolls (they cannot use spell completion items) but can learn formulae from them like wizards do. So, a sensible thing for the alchemist to do is buy the scroll, make their Spellcraft check, and then sell the scroll back (since they can't use it). They pay the cost of transcribing the spell, but otherwise get it for free. Is this "working as intended?" Should there be an additional cost? I'm fine either way, just checking.
I think this is the relevant text:
An alchemist can also add formulae to his book just like a wizard adds spells to his spellbook, using the same costs and time requirements.
Emphasis mine. Part of the cost of a wizard adding scroll spells to his spellbook is that the process consumes the scroll. Barring some other text that says alchemists somehow save theirs, I think they lose scrolls in transcribing them, as well.
A second question is the copy of a formula list or spellbook. How is the time to make a copy handled?
Are you talking about learning, or just flat out copying? My assumption is that there's no appreciable time involved in making a copy of your formula list, since you don't have to learn them again. I could see a GM ruling you needed to take extended time in-adventure if you decided to make a copy spontaneously, but outside of an adventure, I think it just costs the price of another book.
Also, we now have "lifestyle" rules that imply the character owns a home of some kind. Can this be viewed as a safe repository for a copy of a spellbook?
I would think so, unless I missed rules for "random B&E of character homes."
For that matter, there seems to be an unwritten rule that a character's wealth is fixed by their adventuring history, implying that items with a monetary value are never permanently taken away (or that full replacement value is recovered). Is there such de facto protection for spellbooks?
I think this may be a fallacy derived from the Wealth By Level limits. If you have an item, then sell it, you get full price for it. You can still, however, lose items or have them destroyed, but you don't gain their worth in that case. You should probably note on your sheet their loss, so that level-up approvals--which try to reconcile your gear with your listed gold from adventuring--can get the accounting right.
Finally, can a wizard or alchemist attempt to learn the same spell from a scroll at a later date? Is there an official rule, or perhaps there should be a guideline of one try per level?
Here's the page you're looking for:
Learning Spells
In LPF, failing to learn a spell, at least by the text there, means you have to wait until your next level to try again.