Many good points , thank you guys

OK starting from the bottom up.
Tom, I have all the tools I need: screwdrivers, knives, ..etc. but a tough and rough tool is always good to have around. I always wished I had one to hammer, chisel, pry and cut or chop something. When you are busy, I mean real busy, it isn't always convenient to go look for something to do this or that. You need a do-it-all tool in your belt for that one-second step to finish the job. I know this because I broke a multitool trying to pry something although I had a 3 ft prybar in my garage.

The hacking knife is very good and worth looking into. The chisel edge can be modified to have an angle.

Back to the Razel
The video has shown me why it is designed with the lower tip more forard than the upper tip ( reverse Tanto ). It makes the lower tip better at cutting boxes. However, I am still not sure that it is ergonomic enough to hold it straight and scrape with it unless you hold it upside down like in the film. Only in that way will the angle of the front edge be suitable for scraping.

That means I should look for a symmetrical handle, not like the one on the Razel. That way the blade can be held right side up or upside down depending on what tip is needed. The handle of most others ( like the hacking knife are symmetrical enough on both sides.

About machetes, I never thought they are soft and springy. Maybe I am not that familar with them. I only concentrated on thickness and making a machete more sturdy by cutting most of the length of its blade.

Comparing thicknesses, the hack knife is 0.25 inches while others are at about 0.075 inches average. That is a big difference.

Oh, one thing I noticed in the Razel video
On the back , the half of the spine that is nearer to the handle , there are some kind of serrations or something. What are these for ? If a Razel is that thick I don't think that was a saw on the back , was it ?