Holly,
The tests are kind of important because it will determine how you treat Richard.
If the tests are positive, you will know that he has a functioning pancreas, unlike the other kitties, and you will have the reason for such a hi dose, plus you will be able to dose more aggressively.
If you read through all of our replies in the link that Ronnie put in her reply before mine, you can see all that the other acro moms said.
Once you find Richard's good dose and he gets regulated, you will find he will likely eat much less. My Oliver is currently getting 23u twice a day and eating about 15-18oz of food, but before, he was eating more than 30oz and was still hungry. My Shadoe also was a big eater before she was regulated, but now if she eats a single 5.5oz can it's alot. The food thing will settle down but in the meantime, you may want to get some friskies, bigger cans as they are good too. Oliver was a feline garburator and would just inhale food, so 13oz cans for a buck were more suiting to my wallet!
If you can set up a spreadsheet to record Richard's BG numbers, others will be able to help you better. It's just about impossible to help without the numbers as they are the way you will see how Richard is progressing.
Please read the below links for info on Lantus; the protocol outlines dosing, when to increase, hold, and decrease, but you will need to know Richard's numbers, specifically his nadir, on which the dosing is based.
Tight Regulation Protocol
LANTUS & LEVEMIR – INSULIN DEPOT –AKA- STORAGE SHED
Lantus&Levemir – Data Ready to Shoot Low Numbers