Reb Shmendrik,
Firstly… the Bobover Rebbe Rav Shloma Ztl was Rav in Bobov for several years. It is true that once he accepted the hanhager as Rebbe, he no longer acted as a communal Rav. However to the chasidim he was always called The Rav….. anyway, i take your point, although i dont particularly agree. I know from experience that if he was doing this strictly because of a doctors orders he would have told me so.As i mentioned, he did explain that the roll was made with fruit juice and was hence a mazonas. On another level,Chasidim often watched their Rebbes intently, learning from their ways and trying to emulate them, here the Rav went out of his way to explain the circumstances.
As for his aversion to sandwiches, he spoke on many occasions to the bochurim that sandwiches were not a Yidisha way to eat. They were created by Lord Sandwich so that he could fress continuously and not even need a plate. This the Rav Ztl said was gluttony and a chosed should try to be more refined in his approach to eating. He wanted eating to be an avodah and not just a means to an end. On the same subject there were many times when he would teach the olam by the tish about proper manners in eating.