Questions about Costco visa

I might become a Costco member in the future & wanted to ask about how their credit card is. Things are still tbd but I wanted to ask some questions here to help make a decision.

1. Is citi inquiry sensitive? My last card was an elan mcp 11 months ago.
2. Is citi cs as bad as they say?
3. Can this card be pcd to another citi card in the future?