New boy with loads of questions!

Hi all. I'm new to the forum and new to Land Rovers. I'm hoping I've just bought a bit of a bargain in a Discovery 2 ES Premium. The garage thought the crank shaft oil seal had gone so I took it off his hands at a 50% reduction in the window price. I've subsequently discovered that the source of the leak is stripped threads on the sump plug! I've decided to replace the sump casing so I can replace the gasket and check the oil pump pulley bolt that I've read can be an issue on earlier models due to a lack of loctite on the threads. Would you guys recommend this course of action or look to remove the old plug and do a helicoil repair? I've a few more questions so any advice would be greatly received. Firstly, the ACE has been inhibited (pump removed and pulley installed) but the original anti roll bars are still fitted. Does this matter? Would replacing with standard ones reduce body roll? If so, what do folks recommend to replace them with? Secondly, the tailgate lower hinge pin looks to have significant wear in it as it clicks and moves about as the door is opened and closed. Is there a way to sort this? I've already sorted the drivers door with the split dowel replacement but think the tailgate maybe different? I can see a small ciclip on the top so assume I need to remove this? The main door hinges appear to be fine with no wear/play in them. Lastly (for this post anyway!), can anyone recommend somewhere that does underbody wax oil treatment in the Leicester/Lincoln area and rough costs of what I should expect to pay? Sorry for the lengthy post!

Welcome, wow, bit of homework to do?? Get it posted on the disco section.