You need to cut in the direction of your body in some cases (for example when carving wood).
Two things to prevent injuries: a) never put any force if the material resists b) do it slowly.
And either learn to sharpen your knives yourself, or take them to a sharpening service. Dull knives require more force, and slip/catch more, so are more dangerous.
The trick I use for doing freehand sharpening is to color the bevel with a sharpie, that will show you if your angle is correct. You don't need a lot of stones, I just have one Sharpal double sided diamond stone, and then I move to a leather strop with 1 micron diamond emulsion compound.
Another very useful thing is an inexpensive jeweler's loupe so you can actually diagnose issues like not having removed the burr.
I looked into sharpening services in my city a few years back and they're like dry cleaners - every one was a mix of satisfied reviews and detailed "this person completely ruined my $600 knife" reviews. It was very off putting.
It's unlikely any sharpener is going to ruin your knife; at worst, they won't put the best possible edge on it. Your knife is probably just an inert hunk of steel. :)
Oft repeated, but I don’t think I’ve ever seen this actually studied in practice. And personally I suspect it’s more a clever meme by knife sellers.
> for example when carving wood
I've watched a lot of shows about the tools used for building log cabins in the pioneer days. I don't even know the names of them, but the tool for taking the bark off the tree by pulling the knife to you as you sit on the log is crazy. Also, the one where you straddle the log and swing the blade towards you between your legs is right up there too. Yet, I can't think of any way of making them better without using power tools.
Drawshave or drawknife and adz.
The drawknife is the safer of the two by far. It’s fairly hard to cut yourself when your whole body is moving the same direction. Similar to using a paring knife in your palm facing your thumb.
The adz however you just have to have good aim or pay the consequences!
Draw knife. As long as you are leaning instead of pulling its relatively safe. Same as its safe to pare by contracting your hand muscles instead of pushing a knife toward yourself.
Draw knives are even safer than paring knives: the handles are placed such that they're closer to you than the blade, it's extremely difficult to get your chest far enough forward that it could contact the blade without a very large chest.