Yes, you can use a fountain pen to write normally. However, you may need to practice a bit to get used to the flow of ink (and also use thicker paper to prevent it from getting stained or spilled). I have used stenography notebooks, spiral notebooks, composition books. It's really going to be whatever you want to use.
There's no rule where you're left with expensive paper. You may need to clean the tip more often if you have problems. If papers with longer drying times give you problems, but you still want a heavier material that handles fountain pen ink exceptionally well, the more absorbent paper used by Write Notepads notepads in their spiral notebooks, notepads and journals is excellent. My conclusion is that it's easy to overlook the meaning of fountain pens with certain combinations of pen and paper, and that you should give yourself the opportunity to try a better paper.
Even 32-pound HP LaserJet paper can make a big difference, and you can use it at work to print special documents or presentations. If you can't stand fogging up or leaking at all, it's best to have a good gel pen as a backup for when you have to use paper that isn't suitable for the fountain pen. These are always difficult questions to answer because (“suitable for fountain pens”) is a relative concept; and (some brands use different types of paper for different products), some are designed with the user of the fountain pen in mind and others are not. I suppose the operating point is relevant, but it's useful to have a mix of f m b pens and not force a specific pen to write on a certain piece of paper.
If you know you're going to be working with paper that isn't suitable for the fountain pen, set yourself up for success by starting with the right pen. A wide, damp pen can cause tarnish even with well-behaved paper, and a thin, dry pen can make difficult inks get along well with paper that isn't perfect.