First try to relax more. If you are analysing you will be tense and the Qi will not flow well. Master Lin says Good, Better, Best.
(1) Re smoke You can do either
(2) Do your best re visualising the tube. Even giving a gentle thought that it is there is Good. Some people can visualise more strongly. Just do your best.
(3) Follow Master Lins instructions re drawing stomach in when inhaling and stomach out when exhaling. He is the Master.