However I have to emphasise that the star rating are relative and I like all the 1 star compositions.
I'll also mention that the opening movement really is the maker and breaker of concertos even more than symponies. As it's the only movement that is guaranteed to be in sonata form. I would generally rate a work with a great sonata form movement over works that are more well-rounded across the symphonies/concertos. I can't imagine any concerto that I would rate 3 star and higher that disappoints in the opening movement.
Regarding violin concerto no. 3 - well it's great but I don't remember any sort of dramatic punch to elevated it higher. Although saying that you just prompt me to listen to segments of that concerto and I'm wondering whether it should be rated higher maybe a 3 star composition. I mean it's a great opening theme and an interesting minor key modulation in the development section.
Sennasides - I really have to look that up and get back to you later in terms of how long it takes until dependence as the resources I have don't have a time frame other than it can cause it. They are really popular in hospitals however that's because hospitals people are given opioids and sennasides are the most effective drug in treating constipation for people on heavy painkillers. I would be far more reluctant to recommend that in the community for anything more than short term management. Although it can be justified for people taking opioids or constipation caused by permanent disability.
Twice a week doesn't sound particularly dangerous to me and that seems safe
The only hint I get is "do not use laxatives products for over 1 week" unless directed by a physician
Although there's nothing specific, my assumption is don't used on a daily basis for 1 week rather than taking it occasionally for more than 1 week. However I don't have anything specific whether twice a week is safe or not