It's a personal decision that you'll have to make - no one can tell you whether to be stricter or not. People can give you the facts, but like everything in life you need to decide what you do with them.
Occasional readings above 7 are still high readings, and still indicate that some damage is being done. The less frequent they are, and the shorter time they last, the less damaging they are. However, I would suggest that even readings of 6.x are not optimal - healthy individuals tend to have a very tight range of blood glucose right around 5, and don't spend much time higher than that.
Any time you spend with high blood glucose increases your risk. That doesn't mean it inevitably leads to a complication later in life; it just means you're at greater risk of those complications. Only you can decide what level of risk you're happy with.
I'm a T1 so in a different situation than you, but if I were T2 I'd do everything I could to drive my blood glucose down to the normal range and keep it there, although I'd look at diet and exercise exhaustively before I added medication. My targets wouldn't be the rather lax guidelines usually handed out, but rather I'd aim for non-diabetic results - glucose around 5 virtually all the time, and an A1C in the low 5's or, ideally, the 4's.
But that's just me - you need to decide what you are happy living with. But if you're looking for validation that running with occasional high numbers is harmless, I'm afraid I can't do that, because they're not.
Hope that helps,
Nick.