I have this jigsaw: Metabo Ste 90 SCS  (610 watts).

So far, I'm using it to cut 1cm to 2cm thick wood, and it's a great tool.

I know that the right tool to cut this beam would probably be a miter saw, but I don't plan to buy one for just a few cuts.

I am not looking for the accuracy of cuts for this job.

I have seen that there are 10 cm blades, but I'm wondering if this is safe to put long blades on a powerful jigsaw, to cut thick - and possibly wet - wood. Some beams are so wet that their weight is almost twice the weight of dry ones.

So here what I fear could happen:

   - violent kickback at some random point
   - blade breaking inside the beam
   - burning or damaging the motor, 

Are these fears justified or not ?