I had umblical hernia surgery over 6 months ago, is it normal to still hurt and feel pressure around the area?

Perhaps. Pain after 6 months is rarely normal. Scars can be tender for that long however. If you are eating well and digestive tract is healthy then the problem is more mechanical, less serious. Scar massage may be helpful. Talk to your surgeon.
Depends. 6 months is a long time for pain to persist, but sometimes if this is very intermittent pain with activity for instance that lasts but a second that may be normal. Nonetheless it should be improving slowly.
Rare. Most people who undergo umbilical hernia repair are pain-free within a few months after surgery. However, extenuating factors may include the size of your hernia, whether mesh was used, the nature of your activity after surgery, etc. The safest thing to do is to return to see your surgeon with your concerns.
See your doctor. This seems unusual and should be improving. If it is not slowly improving or is getting worse, i would definitely discusses with your surgeon.
No. Pain and pressure six months after surgery is not normal. Perhaps a sensory nerve was injured and became entrapped in scar tissue. Your surgeon should evaluate the problem in order to possibly treat it.
This is not uncommon. Pain from umbilical hernia repair is not uncommon. The severity and duration of the pain depends on surgical technique, mesh, and body habitus. When significant pain lasts greater than 3 months revisional surgery may be useful.