Re: 3/3Max AMPS 262 +4=320 +6.5=245
you said in the first post today that he is acting ok - is that still true? if so, we just deal with the BGs. If he's acting sick or off, that is different and a vet visit might be in order.
i think you have increased him very appropriately, so no, i don't think he's getting too much insulin. that's usually seen when people increase too quickly or by too large of increments. sometimes people increase by a whole unit, for example.
i wouldn't worry at all about the insulin being left out for a few hours. in the paperwork, Lantus says it's good for 28 days kept out at room temperature all the time. i've left vials out before without a problem.
I wouldn't blame the insulin not being good either, if that's what you're thinking. Does he have any history of bladder infections? sometime a UTI can pop up in our diabetic kitties and that can increase BGs. Symptoms would be urinating often, out of the box, maybe even straining.