[Suicide Junkie]

Adding moons with atmospheres is a simple matter of adding to the SystemTypes.txt file. Copy a moon, and set its size to small instead of tiny, and set its atmosphere to whatever.

Although you could have tiny moons with atmospheres, it would be odd IMO.

As for all the new planets we've found, They all are larger than jupiter, so it would be nearly impossible for them not to be gas giants.
Note that we don't know what the planets are like, other than their mass and orbit. It is just hard to see how a world bigger than jupiter could form as a rock or ice world.
All the planets are excessively huge because of the way they are found. We don't have the current ability to detect earth-size planets in general.

Methods for finding planets:
- red-shift wobble: as the planet goes around the star, it tugs the star towards and away from us, leaving a periodic shift in the color of the light from the star.
- Spacial wobble: It may be possible to detect tiny variations in the stars path against the backgroud, as the planet tugs on it.
- Light Intensity: When the planet passes between the sun and us, it will block a small fraction of the light, and the star will appear to dim. This only works if the planet's orbit is aligned right, though.
- Direct imaging: Look at the star and blot out the light from the star. If you see anything, you may have a planet. Note that this cannot be done conventionally, since the separation of the star and planet is too small. Interferometry, can be used in this way, though. With two telescopes, you can get the light from the star to interfere and cancel itself, leaving only the reflected light from the planet which is at a slightly different distance.