Re: Beginners with delusions of grandeur...
There is one thing that - for me - makes a very good teacher: to know exactly what tip each student needs at what time. Dave Lowry wrote about that in his book Moving toward Stillness - it is the chapter called Sottaku doji. It is excellent reading.
IMHO only your sensei knows when it is the right time for the right tip. Of course your sempai can help, and it suree is great fun to play around on the mat with a friend, gently blocking, giving each other tips, etc. But there is nothing like the tips I get from sensei. Even though you might have experience in other MA, you certainly havenīt got the knowledge of where the individual student is at and what he/she can handle. Therefore IMHO you should be quiet unless your partner asks you for help.
Just my two cents.