There's a general acceptance that many scorpions can be kept communally until they can't .. This means that some people might experience they have no problems with, lets say C. bicolor being kept together while others may experience cannibalism amongst their scorpions...The size of the enclosure and amount of potential hiding areas coupled with available prey items all contribute to whether scorpions will leave each other alone....Other factors such as environment and stress could probably also have a role to play.
Many species prey on other scorpions .. especially arid species where available prey items could be hard to find. Also, as in many other species of inverts, scorpions are particularly vulnerable when moulting and for a few days after moult when their exoskeleton is still soft. A scorpion in this state of it's development will be an easy meal for many other scorpions.
Therefore most scorpion keepers will always separate young animals regardless of whether or not that particular species is considered communal.
On the other hand there are quite a few species that will tolerate each other when they first become adult although, as i stated earlier, certain conditions must be met for this to be successful.
Hottentotta species for example (yes, i know they are not on your list) are quite often housed together as adults while other species (androctonus for example) might only be kept together in pairs (male/female) and even then most breeders would remove the male shortly before the female gave birth.
Of the species on your list i'm only really experienced with Rhopalurus garridoi, princeps and junceus. I have heard that junceus can be quite cannibalistic although to be fair i haven't experienced this in my own scorpions .. I also house garridoi and princeps together but again.....only as adults......I wouldn't house any young scorpions together regardless of species but that's just me...maybe there are other keepers who do it differently.
The remaining part of your question regarding temp and humidity is to nuanced to be able to give you a 100% answer.....Basically you want to reproduce the environment that the scorpion comes from..although even dry areas sometimes experience rainfall and hot areas can also experience cold periods...For most scorpions i would say that temps between 25 and 35 degrees are going to be either spot on or at worst, acceptable.
Scorpions have the ability to regulate their body temperature within certain parameters so to say for example that R.garridoi (that comes from Cuba) must have a temp of 27 to 30 degrees coupled with a low to medium humidity (garridoi is found in coastal desert regions) would be incorrect. Fluctuations and variations will be more the norm with seasonal changes also present.....This simple fact is applicable for many species.
With regards to humidity though most keepers will try to increase the humidity slightly when a gravid scorpion is approaching her time as well as when young instar scorpions are in pre moult. The increased humidity helps scorpions get out of their old exoskeleton although again the level of increased humidity will be slight...Many arid species for example are at risk from mycosis if their environment is to humid for to long a period.
Lastly...it's good that you ask these questions although i feel many of the answers you are looking for can be found by simply typing the species in google and adding "care" or "caresheet" at the end ... or ... reading through past entries on this forum as well as other forums such as The Venom List and Arachnoboards..
