If he's hissing at you it might be better not to chase him around the tank; he might perceive that as a threat. If he's only that little it might be better not to hold him right away. Younger bearded dragons are often very bold and will threaten to bite when you put your hand near them from what I've been told, which is a good sign because it means they know when something might be dangerous.
You chasing him around the tank might be making him worse; if he doesn't want to be held, don't force him. Let him come to you; continue hand feeding him, but try hand feeding him while he's in the tank as opposed to taking him out. If he turns down the food, don't try to force him to take it. Place your hand down on a surface near his head with something on your index finger; he'll eye it and if he wants it, he'll take it. When you hold him, if he squirms and tries to jump away, put him back; don't let him escape and don't chase him around. Later, when you're comfortable holding him, then you can begin training him to understand that squirming will do him no good. Definitely do not put your hand in front of him if he's agitated already, because he will probably bite you.
I think you're just scaring him and stressing him out by trying to force him into contact. Build up his trust first — baby steps, only handle him if he'll allow you to — and when you hold him, make sure he's in the palm of your hand. Gently wrap your fingers around him so his head is out and maybe bring him to a darker area; the dark seems to help them relax a little bit. Archaeon always closes his eyes and gets really comfy in dark places. Stroke him gently — be careful of stroking his beard, if he seems squirmy or agitated he might just bite, but I find it helps to offer my finger to Archaeon so he might lick it and recognise my hands — but be very gentle and calm. Definitely don't move your hand too quickly and don't make sudden movement, especially when holding him. Try to keep the area around you quiet, and don't rush into forcing him to trust you. Let him come on his own terms.
I know you need to be persistent, and I totally agree with that, but don't do it all at once. Archaeon has never once opened his mouth at me, or hissed at me, or threatened to hurt me and I've let him come to know me on his own terms. Also, if you do get him out without fuss, I'd suggest taking him to a room like a bathroom (especially a
bath tub, that's where I always take Archaeon), closing the drain and sitting on the side with the drain so he doesn't hurt himself, and maybe putting him on your leg. If he jumps off and runs around the
bath tub, that's all right — if he seems to be getting stressed, veeeery calmly take him out and return him to his viv — and will help him get used to your presence. You could also try gently wrapping him in a dish towel over something, to help him bond with you.
Good luck with your beardie!
I'm sure he's just skittish because maybe you're a little overbearing, and definitely intimidating. Give him time!