1*You could say the same for the engine or transmission. There's no kick stand for the FEL, it's not designed to be removable.
2*Well, lighter is a bit of a stretch, what is the most we could be talking about in the mounting, 10-20 lbs? It's not often that makes a difference. I've never hooked up with the JD system (my 955 didn't have it), but I'm not sure how it could actually get any easier than the SSQA. I'll also give you that you can probably find every attachment with a JDQA equivalent, but you're missing the point. For better or worse, SSQA is an industry standard. There are 1000's of new and used attachments for every JDQA out there. That absolutely drives price on both new and used. You may have an option with JDQA, but you'll have 10 model choices and a much better chance of finding a good used attachment with SSQA. Now that JD is starting to move over to SSQA, it seems like it's only a matter of time before JDQA goes the way of beta max. Check out the inventory of the worlds largest equipment auction to see how much SSQA is available, I bought a set of heavy duty forks that way, brand new for $450 and they match up to my tractor (capacity wise) very nicely.
New & Used Skid Steer Attachments Equipment for Sale | Ritchie Bros. Auctioneers
I give you the point on hydraulic fluid with rental attachments, 100% valid.
3*No, but I am pushing 'not ONLY a JD'. It's his first tractor. I was in that boat about 4 years ago, when I started shopping, I knew nothing (and had never heard of TBN). I was only buying green or orange, and not the orange I have now. Was my 955 a mistake? I don't think so, I learned a lot from it, but it's nothing close to the tractor I've ended up with. There are a lot of great choices, but it's very hard for a first time buyer to understand that, all they know is that the house hold names in tractors are JD and Kubota. There are a lot of others and they should not be overlooked. I'm partial to Kioti (Daedong from South Korea), and you'd have a hard time arguing you're not partial to JD. The OP needs to look at ALL his options to figure out what he'll be partial to.