Citizens arrests are generally legal, but it would be illegal to move him, you could only detain him until LE showed up. See if you could get former leo to train you to use them. Proper handcuffing is generally done very quickly, most of the trainees who were with me could get in and out of a persons bubble in less than 5 seconds. Once you get one cuff on a bg you can usually manipulate them easily if they start to resist, I was certified in handcuffing when I was 18 but there are alot of things to know before you actually go try to handcuff someone. Just to throw a few out there:
Handcuffing and uncuffing is one of the most dangerous situations an LEO ever gets himself into on a daily basis.
Handcuffs are a deadly weapon, once you have one cuff on, if you lose control of the suspect and have to disengage you should immiadiatley go for your sidearm.
Any time you step into a persons bubble (if I rememer correctly the kill zone is anywhere within a 6 foot radius of someone) you are putting yourself in danger so you want to get in and out as quick as possible.
You never know whats going to happen so keep them, but I think for a civilian it would make more sense and be easier to just make them lay on the ground and hold them at gun point until LE showed up