Pit the rust, if it's deeper than a dime skip it.

Velcro ties are fine, the hum is a separate thing and you already figured it out. Power next to signal can cause noise, sure, but the tie itself didn't do that, the placement did. I've used cheap velcro for years on everything and the cords come out fine once you pull them off slow instead of yanking. The crease you're seeing is usually just the cord sitting tight for a long time, and it goes back to normal if you leave it loose for a day or two. The real fix here is running the power cable down one side and the signal cables down the other, then you can bundle each group however you want.

The 10x50s have a spec the cheap 70mm scopes usually can't touch: a 5mm exit pupil, which means the full light cone hits your eye. Most of those $150 refractors ship with a 25mm eyepiece that gives you like 28x, and a .5 degree field. Finding Andromeda in that is actual work. What you built from your patio is a finder, and that's not a waste. Get a decent star chart, learn the sky with both eyes open, then buy a scope in a year with your list of targets already made. People who skip the bino step spend their first month just hunting for stuff.