I'd like to book a flight from YVR or SEA for four - anytime in 2019 in business class.

I'm executive Platinum, 16-500mileTokens + 4-systemWideUpgrades

AA: 266k points
Chase Reserve: 100k points
Amex Plat: 100k

Objective: Don't want to spend anything if don't have to. My issue is I found out you cannot use your 'systemWideUpgrades" on AA unless you buy the ticket with currency.
Question1: Can I buy the tickets with Chase portal instead of AA points, or would the system know? I suppose it would as you have to use the tickets there and then.

If above is not possible, that makes the systemWideUpgrades useless to me, so ill just use them up for work one day which is a bummer.

Question2: Looks like I'll have to buy business class via mileage points. Are there any deals or 'special fares' or can you reommend another airline I can convert AA points to another (say avios) and buy business class that way?

What would you do if you have the points mentioned above? Booking through AA.com I'm pretty much stuck having to fly economy-plus at best (as I cant use mileage or systemwide). Maybe Chase portal or Amex portal have better fares? Or maybe I can convert amex/chase points to avios?

I notice lufthansa or british airway has many flights, is there a way to move AA to British airway or lufthansa via alliance or oneworld?