Does anyone know the experience conversion between rogue trader character and DH 2.0 characters?

It is two very different character progression systems. Why don't you import the rogue trader parts you need into DH2 and assign some DH2 aptitudes and costs to them?

I'd simply rebuild the character concept through 2.0 and give them plenty of influence. Keep ship combat as Rogue Traders. They're just incredibly different systems because of aptitudes vs ranks.

Warning: If you rebuild Rogue Trader via this system you may be denied the joy of giving Fantasy Flight $60 for their Rogue Trader 2e update in 18 months.

No need to be sarcastic.

I'd simply rebuild the character concept through 2.0 and give them plenty of influence. Keep ship combat as Rogue Traders. They're just incredibly different systems because of aptitudes vs ranks.

It's a little more than that. A while back Plushy did an OW conversion for rogue trader that pretty well covered aptitudes and such. Additionally, A RT character is stated to be the equivalent of a 5000 pt DH character at creation! Furthermore,

Profit factor is similar to influence but not the same. Profit factor deals with a scale of wealth not even imaginable to an individual influence rating. Inquisitor's and rogue trader's are powerful for different reasons. Inquisitor's, while by no means poor, are more about political power than shear wealth. RT's on the other hand, are all about the AMOUNT of the check! (To Paraphrase an old movie!).

Warning: If you rebuild Rogue Trader via this system you may be denied the joy of giving Fantasy Flight $60 for their Rogue Trader 2e update in 18 months.

The actually already released this game. It's called Edge of Empire.

Really, well then they won't get my 60 and however much it is for the special dice.