It's been years since shop listings didn't appear in general searches. The recommended number of listings for a store is supposedly 100+.

Personally, I wouldn't try to compete with Chinese sellers on price. Try upping your prices. As you said, you have the advantage on postage times, so buyers should be prepared to pay a premium for that.

No idea about powerseller. A lot who get it come on the boards whinging because they don't get free listings anymore. As long as you tick all the boxes, PS will also give you Top Rated Seller status, which allegedly engenders trust with buyers.