Is the DWE4222N good for cutting steel?

Yes. The 11 amp motor and 11,000 RPM spin 4-1/2 inch cutoff wheels fast enough for regular steel cutting. Use the correct wheel for metal and let the tool do the work.

Does it have variable speed?

No. This model runs at a single 11,000 RPM. If you need slower speeds for polishing or wire brushing, look at a variable-speed grinder.

What size wheels does it take?

It takes 4-1/2 inch (115 mm) wheels with a 7/8 inch arbor, the most common size for this class. That covers cutoff discs, grinding wheels and flap discs.

Corded or cordless: which should I pick?

Corded suits long grinding and cutting sessions where an outlet is available, with no battery swaps. Cordless gives more freedom on site but adds battery weight and cost.

Is it worth it over a cheaper 7 amp grinder?

The extra amps keep the wheel spinning under load, so it stalls less on thick steel. For occasional light work a smaller grinder is enough; for daily fabrication the extra power pays off.