Newbie questions

hello guys i have just taken the plunge into newts and have a 20 gallon setup with two alpine newts. I have a few questions i hope i can get answered.
firstly one of my newts hates the water if he touches it he pulls away and if he falls in he swims frantically until he gets back on land which for the moment consist of a piece of drift wood sticking out of the water .When i read the care sheet i though it would be best to keep them fully aquatic but after seeing this newts reaction i thought i would be cruel to deny him land. my other newt loves the water and stays there all the time both eat live blood worms. is this normal?
second i have read that species mixing is not advisable but what about jap fire bellies and alpines? or white clouds and alpines?
also how do i tell males from female alpines my two have a drag coloration but noticeable swollen tail bases making me think they are males.
thanks allot guys

How old are the newts? Juveniles tend to be land-lovers.

No, you cannot firebellies with alpines for numerous reasons: their toxins are completely different, and potentially very toxic to each other (The firebellies being more toxic than the alpines). Then, you run the risk of two species not recognizing each other as 'friend', and fighting. Neither species is very aggressive to their own, but they may be aggressive to others.

As far as white cloud minnows, this is marginally acceptable, as long as you're willing to risk losing some as a snack.

thanks
the newts are only about two years old.the land newt as i like to call him will venture into the water to eat if i place worms in the knock just under the water.