DS250 2007 Shifting problem & Idle issue

I have two questions that I cannot find an answer to. The first one is that when I shift in reverse nothing happens. I have to rev up the engine and then it pops into reverse spinning the tires. It’s not smooth like shifting into drive and it only does this in reverse. Is this a simple adjustment issue?

The other problem is when it is idling it misses every now and then and almost stalls and actually does stall when I come to an abrupt stop. This also happens when running it down the trails at various speeds. I have changed the fuel filter, flushed the old fuel out, cleaned the spark plug, and adjusted the fuel mixture and idle screw. This did make a huge difference in the way it runs; however, it still misses every now and then. Any advice would be greatly appreciated.