I haven't seen outdoor food courts in Ontario Canada. But you don't need a membership to go to the pharmacy, and I'm sure they'd let you in for free for the food court. In California, in addition to the pharmacy, there was no membership required for buying alcohol.
No, you don’t. If you know someone with a Costco membership and they buy you a gift card, you can get in with that.
Even if the gift card is only for $10 or $20 and you want to buy things worth more than that, you still get the membership prices and pay the difference by credit card.
At the Costcos I’ve been to the restaurant is outside the members-only area.
Here in Calgary, you don't need a membership for the food court, pharmacy, eye clinic, or customer service. Customer service would be where you would sign up for a membership anyway