How many?

Hello everyone.
I'm brand new to the forum, and to newts. However, I have kept fish for many years, and know quite a bit about good pet care, tank maintenance, and that all-around most important quality: patience.
Last week, I got a Chinese firebelly newt, which I am now keeping in a semi-aquatic 25 gallon, fully cycled (it has been running for three years, with fish I took out and moved to my other tanks). I also have two minnows in there, and I plan on putting in at least another three, for a total of five minnows. The newt has two big logs sticking out of the water, with a few hiding places, one of which she has already adopted as "home." I have a heater, set to 70, but wonder if I need it at all.
Anyway, my plan was to see how this one adjusts, and how I adjust to newt-care, before I add some more. It is active, and has been eating frozen bloodworms. The minnows feast on the leftovers. And now, for the questions:
1. Do newts like company? Should I buy another one, or two? Do they have to be a heterosexual couple?
2. This newt is still very young, and small. All I'm feeding so far is frozen bloodworms. Should I vary its diet?
Looking forward to your answers and advice.

No heating is necessary. Most newts don't need company but a 25 gallon setup is rather empty with one newt and five minnows.
As an alternative to frozen blood worms you can try live black worms or chopped earth worms.
Check out the articles on www.caudata.org/cc for more information on chinese firebellies (cynops orientalis).

I think the newt I now have is a female. I'll try and make sure. Does it matter if my next one is male or female? I have no intention to breed them. However, I also don't expect that simply having a male and a female would necessarily result in babies, right? I mean, newts are not like guppies, or are they?
A couple more questions: I have a small, shallow water fountain in my front yard, with a few water hyacinths, but no fish. Mostly, the birds use it as a bird bath. Can I bring in a small water hyacinth for the newt? Also, there are tiny wiggly fully aquatic worms in the fountain bowl. Would it be safe to give them to the newt?

Chinese Fire Belly can be like Guppies. Just the babies are harder to raise. Male or female is not a matter.

Nada, I don't think your newts will have babies unless you try for them to. They may lay eggs, but I doubt many (if any) would survive without you removing them from the parents and feeding them appropriately (very tiny food).