I know this is not a pepper forum, but the question is on the way Tomatoes are planted.
So I think that you should know the answer, as well, if not better then most.
Here is a link to the 2 FAQs on this question from over on the Peppers forum.
Here is a link that might be useful: How to transplant peppers FAQ
I'm a pepper nut myself. Peppers can grow roots, but not the way tomatoes do. They usually only grow roots high when the soil is too wet and they aren't getting enough oxygen, and often above the soil line. Peppers usually don't stretch like tomatoes either. They usually stay relatively short and are usually self supporting. If you have particularly dry soil such as sand, you can plant them deeper to put roots further from the dry surface. In most cases, it's not really necessary, but it does no harm either if you want to keep your plants short and your water table isn't too high. The only thing to watch for is that some varieties of peppers grow long and touch the soil if you go too deep. You don't want that. In containers, which often works best for peppers, you won't be able to plant them much deeper in most cases.
Check the FAQ as well.
I think you can do that but I have never done so with my peppers. I just plant them at the same level they were in the seedling container.