Keeps 4 days refrigerated and is genuinely better on day two — the flavours settle and the meat softens further. Freezes 3 months. Potatoes can go slightly grainy after freezing, so some cooks freeze it without them and add fresh.
It usually needs longer, not less. Connective tissue turns to gelatin somewhere around 2–3 hours of gentle simmering — if it's chewy, keep going. The other cause is boiling rather than simmering, which tightens the muscle fibres.
Yes. Brown the beef in a pan first — don't skip it — then 8 hours on low. Add the vegetables for the last 2 hours.
Not enough reduction, or too much liquid to start. Simmer uncovered for the last 20 minutes, or mash a few cooked potatoes into the broth to thicken it.