One way of playing is to make lots of money safely, and leveling up equipment and skills to a level you feel is safe. And then start adventuring into the caves. It certainly is perfectly feasible, but for me it would make the game too safe and too boring.
There are people who play without using any smithing or enchanting.
The way I have been playing is I go on different adventures and gradually level up my combat skills. Most of the time I feel okay and don't feel too vulnerable. And once in a while I get into a situation where I feel very inadequate.
When that happens, I take a step back from adventuring and go back to doing safer things for a while. I'll level up my crafting skills and make better gear, and maybe level up my combat skills safely by fighting weaker enemies.
With crafting, I noticed that there is a point when things you make are so good that the game becomes too easy and boring. When that happens, you can turn up the difficulty level or intentionally use less effective gear.
Someone told me that having armor rating that's 10 times your current level is usually adequate. As you level up, you have to worry more and more about magical attacks and start building up magic resistance. I usually feel most vulnerable between level 20 and 30. Things get easier after that gradually. And pretty invulnerable once I max out my enchanting and smithing skills and have pretty good combat skills.