So I currently have 43000 points in my Marriott account. I'm waiting for the 70000 bonus from the Chase Marriott card to roll around to get a total of 113000 miles in my account. I'm doing this so I can transfer 112000 Marriott points to 50000 United miles. I fly United a lot and I don't have any interest in staying at Marriott properties (got the 43000 points from business trips). Is this a good way of using my points? I know you can do the 7 night vacation and miles package for better value but again, I don't plan on staying at Marriott properties. The Points guy values Marriott points at 0.7 cents per point and United points at 1.5 cents per point so it looks like a fair transfer ratio is 2.14:1. If I do the 112k to 50k transfer I'm getting a ratio of 2.24 which I think is fair.
My second question is once the AF rolls around, can I downgrade this card to something else? I don't want to cancel the card and lose the credit line.
Thanks!

Although I use my Marriott points differently (I do stay at Marriott hotels, and I sometimes do use the travel packages), I tend to feel that it is a good use of your points if it meets your travel goals and you are satisfied with that redemption.

About cancellation: Chase is very good about allowing you to transfer your credit line to another Chase credit card. So if you decide to cancel your Marriott credit card, but have another open Chase credit card, I would ask the rep to transfer your Marriott credit line over to your other card(s). That way you will retain all of your Chase credit line. In the future, if needed, you could then transfer some of that retained credit line to a new credit card account that you might wish to open.

Normally I am against transferring MR points to the airlines at that ratio, but given your situation, since most of the points are from a signup bonus, and you are just looking to take them off your hands, it doesn't seem like a bad idea. Not ideal, but not really sure what the alternative would be. There is also another Marriott card with a lower AF than the $85 on the Premier but the perks are also lower (no free night, fewer elite credits, etc.) What benefit were you looking for in getting the card if you didn't plan to stay at Marriott properties? You could have gotten a CSP which has points transferable to United at a 1:1 ratio, or one of the United cards that Chase offers, but I have zero knowledge about either of those since I'm primarily a Delta flyer. Other threads have reported that it is difficult to product change the Marriott card to other Chase cards outside of the Marriott family.

Not sure how much 50,000 United miles is worth to you. But I equate 113k in Marriott points to about 5 or 6 nights if one is not real picky.