Problems with scorching on brew kettle

Hey everyone,
Its my first post here and I just got my fourth batch into the fermenter. This batch used a new brew kettle considering the old one was an ancient enameled kettle and was chipped and flaking (not good flavors, I suspect). The new kettle is Stainless and holds 5 gal, and is rather thin. I noticed when I was cleaning up that there was scorching in the pattern of my electric stove element on the bottom of the kettle.

Do I need to worry about this? Will it impart an awful burnt flavor? Will there be chunks of burnt extract floating around in the beer?

If I do need to worry what can I do to avoid this in the future? This last boil was 4 gallons and I needed to keep the stove on high just to keep the boil going. I assume this is because the kettle is so thin and therefore losing a lot of heat. Is there a good way to insulate a kettle like this?

Please advise!

1. When adding LME you may want to turn down the flame, mix in the extract very well, and continue to mix for a few minutes after turning the flame back up.

2. When using LME or DME you can keep the lid on, slightly ajar, as you are only concerned with hops utilization and sterelizing the wort, you don't have to worry about driving off DMS.

I usually don't keep a lid on the kettle because in my experience so far, it has always boiled over when I put the lid on. Maybe there is a trick to keeping the lid on and not boiling over, but I don't know it.

Does your #1 imply that you think the scorching happens right when the extract is first added, and that when well mixed there will be nothing to scorch?

I think in general I would like to boil with lower temps (closer to actual 212degF), so I will experiment with insulating the kettle. Maybe a towel wrapped around?