Jim,
Wow, lots of questions that are the very root of running fixed assets. You would be well advised to get your hands on the training manual and run through the exercises therein.
Integration with A/P
You will set up a 'trigger' account that will also be used as the clearing account on fixed assets account setup. Whenever your A/P clerk puts in an invoice for a fixed asset, she/he will debit the 'trigger account' NOT the fixed assets account. The amount of the invoice, along with other information will be written to a table that you access from the Fixed Assets General Information window. When you capitalize that item into fixed assets, the entry created will credit the trigger account and debit the fixed assets account.
Integration with PO
You have a choice here that you need to declare in the company setup window for Fixed Assets. You can either use a trigger account for the debit, or you can mark a specific line as a capital item by checking a box on the line item detail entry.
Depreciation Integration to GL
YOU will run the depreciation routine to calculate the depreciation. YOU decide when you want to create the GL entry and then transfer it to the GL module.
You say this is pretty straightforward, but each of your questions reveal that it is not as straightforward as you might think.
Fixed assets is a very good module and once you have it set up correctly it is seamless. You have received good advice in this series of posts. In my opinion, the mystery to fixed assets is having the right number of classes. Group your assets by depreciation method, life, and gl accounts (and insurance class if you are using them). Where they are EXACTLY the same, you have a class.
You may want to run through a couple of depreciation cycles in a test company so that you can see how all of these settings interact.
Kind regards,
Leslie