Do these skates run true to size? if i wear a size 11 shoes, what size skates should i order? thank you!

The rule of thumb is 1.5 sizes smaller than your shoe size. However I did just that and these skates were way to small. Had to return them. I went to Dicks Sporting goods, tried on a few different sizes and ended up getting a size exactly to what I wear in shoes.

Do the insides have a cushioned bottom and what is the arch support level: none or some?

Hello, Please refer to the skate description: Thinsulate® lined upper and tongue with cushy foam padding for maximum comfort and warmth • Modern look offering reduced weight due to lightweight construction • Durable nylon upper with color coordinated trim • Synthetic outsole for reduced weight • Leisure blade with stainless steel runner

My son wears youth 4.5. What size would I order since that is not an option?

Good morning. Thank you for your interest in our Softec skates. Typically you would go down about 1/2 to 1 full size from shoe size to Jackson skate size. If your son has average width feet, then a size 4 would most likely be a good fit. Unfortunately as everyone's feet are different it is not possible to provide a skate size to you that is 100% guaranteed to fit. Sometimes, if people have issues with getting a good fit for shoes, they may also have to try a couple of sizes before they get the best fit in skates. Kindest regards, Customer Service, Jackson Ultima Skates