Luna Moth Wings+Chaurus Eggs=Expensive Invisibility Potions, both incredients are quite common. Alchemy is the easiest crafting skill to level up.
They definitely over-did smithing. Yes, it was probably a bit easy before, but now its impossible and one of the hardest skills to get up when its over 75. Sorry, OP I don't know any new ways to get it up other than grinding.
Only because you don't know how to level smithing post 1.5, if you did you wouldn't say it was hard. I bet you only craft armor and never bother to improve the items you make at the workbench or grind stone. Including the Oghma Infinium smithing has fourteen free skill boosts for smithing, five books, four quests and of course +5 from the oghma infinium. Once you hit eighty you can head to Gloombound Mine, grab some ebony then craft and temper ebony bows. Tempered ebony items are worth FAR more then the value of even buying the ebony igots.
So many people forget to temper the items, its more cost efficent then simply crafting them, especially if you manage to get a few fortify smithing items.