InVinoVeritas
Adventurer
Neither of those are G sounds. Roger is pronounced with a J sound, and 'rouge' is pronounced with a sound that English doesn't have a letter for. You might compare it to the J sound, but it's nothing like G. S and Z, and T and D sound more similiar to each other than G does to that sound.
The soft G sound is the J sound. Similarly, the soft C sound is the S sound. The hard G sound is the G sound of "grade," and the hard C sound is the K sound. That's how I learned it in first grade.
English has more sounds than letters, so double duty and swapping happens all the time. It's the effect of having a Low West German language absorb bits of Celtic (Brythonic and Goidelic) before being socked in rapid succession by a North Germanic tongue and a Langue d'oil. Live with it. The language's loose, modular approach to vocabulary has allowed it to become a major world language instead of just something half an island speaks.
The sound G makes in "rouge" I've heard described as the "ZH" sound. It is the sound S makes in the word "treasure." I think ZH was second grade.
Rogue rhymes with vogue. The "gue" construction is vital because the U gives the G its hard G sound, and finishing with a silent E making the vowel sound before the G long and the U silent. It's something English picked up from the invading French. It's used in other words like "plague" and "fugue."
Sure, English is a hot mess, phonetically. I always feel for anyone trying to learn it as a second language. However, the language is still mostly logical.
Oh, and just to help out the its/it's question:
His, Her, Its.
He's, She's, It's.
That's it. It's that simple.
Yeah, the rule I learned in second grade (third?) was that possessive pronouns don't use apostrophes, but I like the above comparison better.