most airlines i've been on are quite accomodating to camera gear being carried on as opposed to being checked in (unless you're talking about those huge pelican cases containing your studio lights and all!) long tripods folded still shouldn't be a problem. I seen people carry strange pole-like objects onto the plane too. So long as its short enough to go into the overhead, I don't think that will be a problem.
I would advise a bag like the CompuTrekker or CompuRover if you're talking about that amount of gear. Or if you prefer sling, the 650 Stealth Reporter. They are all able to go into your overhead without too much problem. Just take note, don't secure the tripod if you're the above-mentioned bags, it won't be able to fit into the overhead. Separate them.
Weight-wise... I think don't worry too much. Mine was about 10+kg in all. The only time when I had a problem with handcarry luggage weight was when I fly with SAF
As a civilian who actually bought the ticket, nahh....
Oh, also I was carrying 2 bags. A CompuRover and another crumpler laptop bag (due to 2 laptops).
Be prepared to take out your laptops and all when going through airport security though. Singapore is pretty strict with that lately.