Generally yes, but with caveats. Loose leaf is usually larger leaf grade, which produces a fuller bodied cup. Premium pyramid bags (Teapigs, Whittard pyramids) close most of the gap. Standard supermarket bags (small round bags) use dust grade fannings and the gap is real and noticeable.

Use 2-3g of leaf per 250ml mug or per cup equivalent in a pot. Pour just boiled water (or 80°C for green, 90°C for oolong, boiling for black/herbal). Steep 3-5 minutes for black, 1-3 for green, 4-6 for herbal. Use an infuser, teapot strainer, or French press to remove the leaf before drinking.

Yes, especially with green, oolong, and white. Most leaves give 2-3 good infusions if you use enough leaf to start with, green can do 3-4 infusions in succession. Black tea reuses less well; the second infusion is usually thin.

2g (roughly a heaped teaspoon) per 200-250ml cup of water. For a 1-litre teapot, 8-10g. Most retailers including us sell loose leaf in 100g and 250g bags so a 250g bag gives roughly 100-125 cups.

Properly stored (airtight, cool, dark, away from strong smells) most loose leaf stays good for 12-18 months from packaging. Green and white teas degrade fastest (oxygen sensitive); black, oolong, and pu erh keep longer. Pu erh actually improves with age over years.