Your arrowsare overspined. It could be caused by a problem with nock point but, most especially with alongbow,the odds are way more in favor of overspine.
About cant... Shooting a compound with all the sights and fooferaw demands a strict adherence to a straight, vertical, mechanicalshooting style. Traditional bows allow for a more loose, relaxed,natural and free flowing style. Again, that's especially true with a longbow. They CAN be shot in that ramrod straight, mechanical style, but why would you want to?
Most folksflex their knees a little to help focus theirconcentration. They lean into the bow from the waist to get the eye aligned over the arrow a little better. And, to top it off, the cant gets the top half of the bow out of your line of vision so you can see the whole target.
Degree of cant varies a lot from one shooter to the next. Here's an old way of finding out how much to cant.
Stand flat footed while holding your bow down at your side, string up. Close your eyes and relax for10-15 seconds or so. Just let your arms and shoulders go limp. Open your eyes and look at the bow. It will usually be at an angle to your body. That angle is your natural cant. Once you've found that natural position, just keep that angle while raising the bow into shooting position, then add the knee flex and body lean.
The flexed knees and the slight bend at the waist makes itlook like the cant is more, but that's only because the body lean is ADDED to the natural cant. The actual arm angle from the shoulder does not change.
ThisUSUALLY works for most people. Not always though. Give it a try and see how it feels.