I think that the solution is have more of the free rental weekends. That gets a lot of players excited about clubs and increases buying.
In terms of ownership, that is a debate. Can you really own virtual avatars, equipment, etc. Well since some or all of the purchase could have been made with real money rather than virtual money, I contend that you can and do own it. The rules are for WGT to make, in terms of trade in, gifting, etc. but I believe we own everything in our account.
I would suggest that the club 'trade in' is a little too low. Should be about 50% of the current cost of the clubs, as you would expect in a golf shop. Since they don't degrade over time, it makes no sense to assign them a used value. I would say that it should be 50% of what the club sells for now not what it was bought for.