All right, here's the deal (and I have used chain saws extensively most of my life)
Most saws these days have a tip guard and I always throw those in the trash first thing.
Kickback most always comes from letting the tip of the blade get below the motor inside a cut.
This means the cut is wider than your bar is long, but as long as the motor stays below the bar tip it will never kick back.
Kick back does not come from, or caused by not butting the motor up against your log.
It IS caused by the tip biting into the log where it can climb out of your cut via the tip of the blade, and if you keep the motor lower than the bar tip this can never happen.
Anti kickback chains were designed to minimize this, but they are for people that don't know how to use a saw correctly.
These work by a fin on the top side of the chain that sticks up higher as the chain rounds the end of the bar, and then it lays down flatter when the chain is running flat allowing the cutting teeth to bite deeper again.
You will see these as what looks like a shark fin right in front of the cutting part of the tooth.
Look at them where the chain rounds the tip and you will see what I mean, as they stick up higher there as each tooth rounds the tip.
Personally I cut those down about 1/16 before I ever use that chain, but cutting them down too far will result in a saw that bites into the wood too deep and stops the chain constantly from trying to bite too deep all at once. as they are a depth guide also to keep from stalling the chain.
This means the saws power is basically the guide to how much you cut them down, and if cut down too far the chain will stop every time you touch the wood with it.
The way I determine if I cut them enough is when I can just lay the blade on the wood and it cuts as much as the motor can pull with NO extra downweight on the bar.
Not recommending you do this, but how I do it is if I only hold the saw by the rear handle it cuts as fast as the motor can pull.
Now, to your specific question.
The chain basically wears at the same rate over the entire chain because of it going around the bar, but it's the bar itself that wears.
I'm sure you have noticed the bar is basically to verticle sections of metal with a groove between them that the chain guides slide along in.
It's those two verticle surfaces that the chain actually rides on top of that wear, and if you always cut with the motor against your log it will wear the bar right in that same area.
Also they don't always wear at the same rate because most people put a little more weight on one side or the other just by the nature of how they hold the saw normally.
When they wear at different rates you will start getting cuts that curve to one side or the other as the bar goes through the cut (most noticeable on deep cuts, as in bigger logs)
Most blades can be turned over so you can have a flat slide surface again when one side wears down.
Roller tip blades are great for added chain life as they cut way down on the friction where the chain is getting pulled against the bar as it rounds the tip.
This cuts chain and bar heat down a ton and extends chain and bar life both.
Safety tips.
1. Always have a working chain brake and USE IT!
Every time you stop cutting and are holding the saw running that chain brake better be on.
I have seen people trip and fall and accidentally pull the throttle from gripping the saw.
That chain brake kept the chain from spinning while them and the saw both landed on each other.
2. NEVER let the tip of the bar get deeper in a cut than where the motor is unless you know what you are doing for sure (I mentioned that already)
3. ALWAYS keep your head and as much of your upper body as reasonably possible to one side or the other of the center of the saw. (kind of like shooting a big gun that kicks hard)
IF something happens like the bar tip grabs another log and you don't notice it the bar can jump up.
You want it go past you on one side and not come up and hit you in the face.
Sounds gruesome, but it does happen although anti kickback chains tend to limit this these days.
Cutting with the top of the bar presents it's own dangers.
It can be done safely and easily, but you better know and be ready for it's own set of dangers.
For one, instead of the saw pulling into your log it will push back.
Having your RPM's up and being ready for the push back are key here.
Also on that note, chainsaws run upside down.
Hints:
We used to use 1 gallon of 30wt engine oil with a bottle of STP in it for chain oil.
It is better for the chain and bar than most chain oils and a lot cheaper.
You will probably never need that much but still, the idea is the same.
Most small saws these days use a gravity feed bar oiling system, and pulling the bar off and running a little gas through the oil tank keeps the oil passage open.
Gravity feed systems plug up easy and this keeps them clear.
A good way to tell if your chain is getting enough oil is to put the tip of the bar a couple of inches away from your log or whatever and rev it up.
You should see small splatters of oil slinging onto the surface from the tip of the bar where the chain rounds it.
Hope this helps keep you and your saw both in good condition.
BTW I used to use my Dad's saw when he wasn't using it. (60 inch bar and 14hp)
I don't think they even make saws that powerful any more.
