I am confused about subscription. So here are a few questions:

1) Which platforms are "Free 2 Play" ? Any time limit on Free 2 Play ?
2) What is the Level cap for free to play, if any ? What is the level cap for Lite subscription ?
2) Can we go back to 'Free 2 Play' after getting a Lite/Premium subscription for a few months ?
3) What ships/advantages does premium subscription offer ?
4) I noticed my green currency count disappears after getting premium subscription. Do I get them back, when I go free to play ?

F2P is mobile only, no time limit. Licenses are capped at 4/4/4/4/4, and you can not hold council or leadership positions in guilds, although you can join guilds as a regular member. Lite is the same, but allows any platform. Yes, you can switch back and forth. While Lite/F2P subbed, licenses above 4 will be reduced to 4. They get restored if you go back to a full sub.

Premium (full) subscriptions have no license caps, can fly capital ships assuming they have built one, and can hold council/leadership positions in guilds.

Thanks for the answers, here are some more questions...

What happens to guild leader/guild council when premium subscription expires ?
What happens to a equipped capital ship when premium subscription expires ?
What happens to a equipped ship/item that requires character skill over level 4 ?

When a full sub expires your guild status does not change, your ships and equipment just waits for you to renew your sub.

I am pretty sure you lose council/leadership positions as soon as you log in on a lite or f2p account.

I can confirm that you immediately lose your guild rank if it is higher than member. My whole SEAL guild was either F2P or Lite except for three of us and the guild folded after only 53 hours because of not having enough council members. Most of our council members were made regular members when they logged back in the next day.

1) Which platforms are "Free 2 Play" ? Any time limit on Free 2 Play ?

Free 2 Play = Mobile only. Lite = Any platform. Full = any platform. No time limit for any tier.

2) What is the Level cap for free to play, if any ? What is the level cap for Lite subscription ?

Both F2P and Lite limited at level 4 for all levels. No council or lieutenant guild positions.

2) Can we go back to 'Free 2 Play' after getting a Lite/Premium subscription for a few months ?

Any time your subscription lapses, you revert to F2P/Lite depending on your previous standing. When you revert to the lower tier, your licenses will reduce and you will lose your guild council/lieutenant positions. Upon resubscribing to full, you will regain your licenses, but not guild positions.

3) What ships/advantages does premium subscription offer ?

Guild leadership, not needing to use crystal to buy ships, no limits on levels. Basically an unlimited gameplay experience.

4) I noticed my green currency count disappears after getting premium subscription. Do I get them back, when I go free to play ?

Subscribing should simply hide the crystal as it is no longer needed while subscribed. Any earned crystal should remain on your account and be re-visible when your account reverts to the lower tier.

Subscribing should simply hide the crystal as it is no longer needed while subscribed. Any earned crystal should remain on your account and be re-visible when your account reverts to the lower tier.

Are you sure that's how it works? I don't have an answer for this, but I'd hate to give a newbie false expectations.

Yes your crystal will re-appear when your account reverts. Also any ships you have in inventory besides capships are still useable even if the level cap prevents you from buying new ones. I started F2P on a tablet and got a friend key shortly after hitting the level cap. When the friend key expired I was flying around in XCs with all licenses at 4. You wont gain crystal while subbed* and you wont gain xp while level capped.

*full subbed. I never went lite

Thanks for clearing my confusion.