#1 Very likely be you have the wrong pull stud or the wrong holders. BT30 and ISO30 look the same but they are very slightly different.

#2 Yes you can get spring-loaded grippers which give a higher degree of flexibility but they are very expensive and difficult to find. However, if you have everything set up correctly regards locations etc then it shouldn't be needed. Alternatively, you could put the tool rack on springs so the whole rack provides some flex.