Hi Jasim!

1) I think it's fine if your palm is holding onto the neck. As long as you're able to play the notes correctly and comfortably, there shouldn't be a problem. The majority of guitar playing is about feel, and there are really no hard rules when it comes to holding the guitar.

Generally, the guitar's neck will naturally rest at the base of your fingers, but!

As a refresher, you could take a look at Lisa's lesson on holding the guitar here: https://www.guitartricks.com/lesson.php?input=21988&s_id=1766

2) Picking is always tough, whether you're practicing scales, a quick riff or anything else. It sounds like you have the most trouble when you're going fast. You may just have to go a bit slower. One of the best ways to learn is to take it really slow and then ramp up the speed gradually.

If you want to get super duper fast at picking, check out Ben's tutorial here: https://www.guitartricks.com/lesson.php?input=23946&s_id=1959

It's pretty intense.

I hope that helps!