Keep your load as low as possible, especially when moving on sidehills, or you'll break more than the loader. Your arm or neck comes to mind.
Try to avoid raising it any higher than the minumum needed to dump it if the tractor is not square up and down any hillside. The tractor is narrow and relatively high centered to begin with. Lifting a good load high when the thing is already tipped due to the hill is asking for a serious hurt, not to mention major embarrassment when you tell the wife you rolled the tractor and hurt yourself in the process, so would she please call a wrecker and an ambulance, in that order.
I used the loader on my Kubota B7100 in all kinds of ways that the guys here now say were wrong and didn't hurt it any. I didn't ram trees or stuff, but I did use it steeply angled for both forward and backward digging at ice on the driveway with no apparent harm. I backed down the hill with the front wheels up and the weight of the tractor on the loader quite a lot. I had bolted foot long homemade teeth on the bucket which I sometimes bent, so maybe they took the abuse instead of the loader frame. I also used it for digging out the occasional rock or stump with one corner or the other, again no harm noticed. This was with the 1630 loader, which only had about a 42" bucket and limited lift capabilities, so maybe that saved me from my ignorance.