no, you dont need other skills, as long as you have enough armor and or resistence, which can be purchased from vendor, to survive, you will destroy foe with combat skill along.
You've clearly been playing a different game...
Without armour skill, any armour sets give you low armour rating.
When sneaking, your crits will be too low to kill without a decent weapon skill, no matter what you swing at them. Unless you use brutal enchants like the one I described, which is no longer do-able.
With magic, you could never get enough mana to cast big spells without enchants, or repeatedly cast smaller spells without drinking pots constantly, a consumption rate that pretty much requires you to make your own, with alchemy.
Have you been playing with your slider all the way left? If so, fair play, that's your choice. However, your experience has no relevance to the rest of us.