Bugger welds like that might be due to too low a power. Does it improve if you crank up the current? Or does it just blow through then?
Make sure your shielding gas pressure is around 6 to 8 psi- seems to work best for me.
You want the tip pretty close to the work- maybe about an inch away. Wire feed speed should be enough to keep a constant pool going, but not so much that it pushes the gun away. Make sure there's no fans or anything blowing on your workpiece.
I've had wire feed issues before. The little wheels that feed the wire do wear out and can be replaced. Also, check the inner metal cable that the wire feeds through and make sure it's not kinked, rusty, or otherwise going to provide resistance to the wire as it feeds. On mine, I've found it helps to make sure the welder is as far away from the work as possible so the gun cable is as straight as possible. Adjust the tension on the spool so it just barely doesn't free-wheel.
Not an expert welder, or even certified, just some things I've learned in my 15+ years of DIY welding with the same Lincoln MIG unit.