To answer your questions.
1. No CEL lights, the car's up to temperature before I even take it to the VTEC cross-over.
2. Duly noted, will have a closer inspection.
3. I have several cars that I drive regularly, but what tells me that VTEC is not engaging is that there's no noticeable change in engine note at 5k, there's no noticeable change in urgency or power delivery either. My 4g, you'd feel the 2nd cam and the engine note would change, that was quite a pronounced difference that the 5g doesn't have. I drove the 5g for a few days in December 2019, put it away for 18 months and then only recently did the restoration work on it. However, the 4g only sold in March and I was driving that regularly so I'm fairly sure I can still remember the cross-over into VTEC.
4. It will go to the red-line, but the power delivery is completely linear from 0rpm through to 7k, there's no change when going into VTEC.
What "might" be an issue is the elbow inlet pipe, which was knackered on mine, so I used them same pipe from a 2.0 but expanded the inlet/outlet flange to fit the larger TBs/venturi on the 2.2. The oil pipe was knackered, splits etc.