In Warp Stretch I try to change marquee size by selecting Absolute, proportional, offset, but I can't get what I want.
What is the relation between the Marquee size and Scale?
I totally agree. I've used it for Industrial Design, but it's not an accurate tool. But for me, it worked great, and I didn't need a particular "number".
I have successfully used the WARP feature several times for compensating cooling warpage of plastic parts.
So you take the creo part and bend it in the opposite direction. This can be done with the parametric model or -since it is only for tooling purposes- with a derived model with a copy geom or merge (since for warping you do not need any of the original features).
The key to getting exact results is to combine it with an optimization analysis.
The idea is to create reference points for measuring on the undeformed and deformed part and create an analysis feature (distance e.g.)
Using the optimization analysis you can then vary the WARP parameter (often a relative one) between a min and a max value so that your measured dimension reaches the exact desired value.
I created a document for a PTCuser lecture years ago (WF2) so it is public. Most of it is still valid.
I just saw that it is in German... I will check if I have an English version as well.