Noticed these bumps a few months back going down my veins down to my hand. Should this be a concern? (Photos)

You shouldn't be too worried. Most of what you describe is related to elevated pressures in your veins, which can lead to dilated segments. Since arm veins decompress easily when you raise your arms, we don't usually see frank varicose veins in the arms but carrying something or having your arms down can certainly dilate up your veins in general. The "bumps" are irregular but since they are not hard and . There are a few conditions such as Thoracic Outlet Syndrome where your vein can get pinched near the collar bone and first rib and can partially narrow your venous drainage (and lead to dilated veins) with or without swelling. This can be evaluated with a simple ultrasound with special maneuvers. Since you didn't mention your right arm and I see a snug watch on your left wrist you should not have anything obstructing on that arm, and should not carry any heavy duffle bags on your left shoulder or extreme shoulder extension such as hanging from a pull up bar. These all accentuate venous obstruction and could make this worse over time.