I sometimes have the same problem of my weight sliding but it only happens when I am using really heavy weights and I don't think it matters all that much if your using over 1-1.5 oz since the bait often moves along with the weight while going through, plus its a reaction strike like if someone throws a baseball at you without a warning, its your instinct to try to catch it.
I never liked straight shank hooks and I use the owners for weightless presentations, but I also like to tie an improved clinch knot or Palomar to save time cause I re-tie anytime I feel like I have taken too many abrasions to prevent break offs, and I would also suggest the bead for 2 reasons.
It protects your Knot, If you put your bait too high up the line to cover or compensate for the knot, then the bait gets bent and that is when I think it can change the action even though most plastics are expensive weed guards or just a place to hide your hook.
Some baits do glide especially on lighter weights or deeper water, so if I am fishing a bait I want to glide like the Gamber Why not, I like it to be straight so it does not spiral like a Tube or crooked bait, I peg the weight really good, but I leave space with a bead and the more space between the eye of the hook and the big weight, the better the hookset from my experiences. If you only have a tiny space from a clinch knot to a heavy weight, I find I miss more hook sets and the hook doesnt kick out right.
I usually will use 2 bobber stops and lock it down if I don't want it to move, the bead adds sound unless it is completely tight, but also allows you some extra space and as long as the bait is going through good on the hook without moving, the weight should be ok even if it gets loose. Its quicker to simply put some living rubber or skirting material in your weight to fix it than it is to tie a snell knot.
I hate tying that knot and never noticed it helping, but I know lots of guys who are better than me who always tie a snell knot, but I think they catch more fish than me because they are more accurate & simply more experienced or concentrate better.
Hope that makes sense, I just rambled off a conversation I have all the time. I use thick guage EWG hooks for big creatures like the BPS Flipping Craws or big salt craws etc.
Some guys throw that Jig rig into heavy cover and that is not going down straight, so as long as your line is not getting frayed, you should be good if you reinforce the weight and just put a bead or some type of spacer.
I am a believer that profile, fall rate, accuracy, sound, right color matter more than if the weight is a bit crooked but I get frustrated as well, it just happens at times, but that is why it helps to use baits that do not slide down the hook easy or are too soft/Thin etc. I trust my clinch knots, Palamar knots the most, especially if using fluoro or mono, Snell knots take alot of time and I don't trust them on Fluoro, only trust an improved clinch knot carefully cinched.
I would also make sure you are using the right sized hook, 4/0 vs. 5/0 can be a big difference, same with guage, that will cause movement as well. I guess it can't hurt to learn the snell knot, for some reason I have always felt it is too easy to mess up and time consuming.