String does not seem to feed automatically frequently have to take the spool out to re thread through the lottle holes

These things can be very sensitive with how the sting is coiled on the spool. Take your time and try to get it perfect. Look at the pre strung replacement spools for an example. also inspect the lever, usually under where the spool sits. Make sure its not to dirty and moves freely. After that when you want it to feed quickly pull and release the trigger a couple times. If you dont want it to feed the when you pull the trigger be sure to maintain how far you have it pulled back, then release it a little slower than usual. Lastly wait a few seconds before pulling again. If this doesnt work the lever may be worn out and defective. But they are super cheap and easy to replace.

One possibility may be that the string has been coiled onto the spool in the wrong direction. Make sure it is coiled in the RIGHT direction. If it won't feed the way it it wound now, try winding the line on the spool in the opposite direction. Also make sure the spool, spring and knob are in good shape.