Well there are two ways to do this time skip.
1. Normal way everyone gets older. This could be interesting the group not getting anywhere with the quest and just chasing false leads.
As to Hal turning into Flax, that could happen but it is not very hard to see him turning into someone compeltely different.
2. The group gets caught in a time bubble where time moves slowly for them. The get out of the bubble and twenty years have passeed, for them it seems like a day or a week (etc).
This option in my opinion has a lot of fun possibilities to offer. With Hal & Drago: Hal thinking hes been out of touch for a week, not twenty years returns to find Drago who believed he was dead. Then finding the galaxy is now a giant slave labor camp to make things worse.
We've been leaning towards this one (at least in the past we have).
Also if you could start making an outline for what you would like to happen in Taris (Going to tie in anything from KOTOR?)
"Dulce bellum inexpertis."
Official Forum Expert on Norse Mythology
As Odin says in the Hovamal:
"Praise no day 'til evening; no wife 'til on her pyre; no sword 'til tested;
no maid 'til bedded; no ice 'til crossed;
no ale 'til drunk."