Hello Josh,
There are a number of very helpful sites that can be used to help establish a wide and knowledge base about batteries and to dig deeper into specific chemistries and scenarios.
I would recommend looking at sites such as:
http://e2e.ti.com/support/power_management/battery_management/m/videos__files/default.aspx
-This is a link to some of the collateral that was presented at a yearly battery deep dive that has a lot of great content.
Take a look at that site and perform some general battery research in the particular area of focus and you will be amazed how quickly some of your questions can get answered.
Looking at some of your questions.:
1. You can consult a number of sources for this including this pamphlet put out by NEMA looking at Pg. 4 point 15. The danger of attempting to charge non-rechargable batteries is in what will happen to the cell which can be disastrous.
https://www.nema.org/Policy/Environmental-Stewardship/Documents/NonRechargeablebat.pdf
2. Each cell has different charging profiles, rates, and voltages. Again the charger IC is a robust device the real concern would be overvolting or overcurrenting the cell that is connect which could cause a dangerous reaction.
3. The charger itself is somewhat removed from the battery using high impedance resistors which reduce current consumption from sensing and would help reduce any issues that might arise from a reverse polarity case on the battery nodes. Again the greater issue is with the battery overheating from the test case described.
4. See point 3
5. Most of the charging looks at the voltage and current that is going to the battery. The timer is more of a safety mechanism to protect the battery from charging too long in case something is wrong with it and it does not exhibit the proper signs to case the charger IC to terminate.
Let me know if you have further questions.
