Yep, you are 100% right, there is a wide margin for interpretation

which, in my case with my drawings, has been quite controversial to many people who have participated in this thread, because... how dare I make the Guardian ALIENS look so human lol.
I would have thought they were mammals - again this isn't really mentioned by Ram Tah, so again there is much interpretation, but he ruled out scales and exo-skeletons with "red skin", so I assume the Guardians aren't reptilians or insectoid since niether of those life forms have skin. He also mentioned the Guardians carry their young until birth, which is something mammals do (don't lay eggs etc). They were bipedal, therefore possessed a back-bone, so again, much interpretation to Ram Tah, lol, but that meant they would have stood up straight.
I do like Remlok Industries drawings, but like many others I feel they have thrown information aside they didn't like, or again, interpreted the information to best fit their analysis (which many could argue I'm guilty of) - the Remlok drawings make the Guardians look like human pop-culture Grey Aliens, which I'm heavily sceptical of when it involves the Elite Universe.
This is the one bit of Ram Tah's info which I feel many people want to ignore, and it is really early in the Biology section at just No. 2:
2) "The information you've uncovered is very interesting and regards the Guardian's anatomy and physiology, you might be surprised to learn they weren't that different to us. Their morphology was bipedal, although they were generally taller and more slender than the average human. Their skin tone was red, encompassing the whole spectrum of red hues. There were various reasons for these changes in pigmentation, including genetic disposition and the fact that they darkened as they aged."
The underlined bit is most important - whereas the rest of the Biology information clarifies what differences there were between us and the Guardians, for all intents and purposes, Ram Tah, I think, is basically saying they looked very similar to us - as in, I wouldn't be surprised if they wore clothing (pelts etc), had hair on their heads, etc., followed by the next 16 entries painting the differences (extra forearm joints, darker eyes, potentially rounder eyes, red skin, taller, slender, lacking a fatty layer, thick skin, serrated ridges to kill and eat prey, proportionally smaller faces - I think that's all of them).
But again, much of this can be open to interpretation because we only have text - but I feel some people are ignoring and favoring some of Ram Tah's biology snippets in favor of others, whereas I'm trying to maintain the whole picture - of course, I could be horribly wrong in both counts (my own interpretation and that of other's use of Ram Tah's interpretation).
Until we get some sort of official art image of what they look like, we're all qualified in imagining what we want

and Frontier may decide to keep it that way...
Still... that won't stop me drawing what I would like to personally see, and that goes for everyone else