All of the options you listed are good ideas. Be sure to find out the company's
flyttfirma Stockholm Better Business rating as well as their reco reviews. Find out if they have a moving license and if they are bonded and insured. You may request to see a copy of their insurance certificate.
Ask them how their movers are hired and trained. Are they background checked? Drug tested? Are they temporary/labor ready employees or full time movers? These things make a big difference.
Find out if the company offers additional valuation for the move. If so, it's always a good idea to take it so that that in case damages occur, you will receive some refund or repair to your pieces.