Oh. my. god. The advice on this forum often borders on lunacy!
First...How experienced are you with handguns? If you are fairly new, the Shield, and most other small size, duty caliber pistols will be a bit tougher to manipulate than a full-size duty caliber pistol. No big deal because it's still a great gun and a little practice will have you running it like a champ. Having a LOT of experience with the Shield and with training law enforcement, user-induced malfunctions occur at a much higher rate than with larger pistols. This just means a bit more training for the user and you will be good to go.
Of course, there could be a problem with your pistol. Some guns do have issues, and if, after proper use it still malfunctions, then send it back to S&W. I bet they will make it right. They recently did with my 342PD I had to send back for a canted barrel shroud.
Are these malfunctions occurring during firing or when attempting to load the handgun? I ask this because your post doesn't make it totally clear.
Secondly... Those who maintain it's a slide-stop only...What is your experience in the combat application of the handgun or in defensive firearms training? The lever on the M&P, Shield, and on most other semi-automatic firearms to include the iconic 1911 is there (among other things) to RELEASE the frigin' slide!!!!!! IF it wasn't, it wouldn't have serrations on the TOP of the lever!!! It's not the only way, but it is definitely "a" way... and if you want to argue fine motor skills, the TRIGGER is a fine motor skill. Landing a plane on the Hudson river or an aircraft carrier requires fine motor skills under stress. So yea...It might be a bit harder than caveman bashing heads in with a stick hard, but we're firing a frigin' gun, not bashing heads in with a stick, so grow up, train, and learn how to use your damn equipment. How many competition shooters (who are by far the most experienced and talented with firearms) slingshot the slide? They DON'T...because it's slower, more inefficient, and hitting the slide RELEASE just isn't that hard if you actually practice.
The following is a picture of a Shield and an M&P compact. At the time this photo was taken said Shield has had somewhere between 14,000 and 18,000 rounds through it. I personally oversaw nearly 6,000 of those rounds and it has had many rounds through it since that picture:
We usually recommend that if the slide stop/release is tough to actuate to confirm the handgun is empty, lock the slide to the rear, and release the slide via the slide stop/release. Repeat this many times and it will eventually wear in. It was the case for most of my M&Ps (I have had six so far) and now they all work great.
As for the failures to feed (FTF), if you are allowing the slide to travel forward under spring tension rather than riding the slide forward (we recommend trying to "rip the slide off the back of the gun until your hand breaks away from the slide") and especially if the FTFs are occurring during firing (as opposed to chambering) then I'd send the pistol back. We had this problem for a while and it seems to be an extractor issue (may also explain the FTE - though not sure if you mean eject or extract) and S&W should be able to fix it for you.
Good luck...Beware of the internet. Hell...Don't believe me either. In fact, just send it back to S&W and sidestep all this internet BS.