If I'm reading correctly, Double Time lets a Transporter use a move action to move double their printed Speed value. In addition, the Transporter move & attack ability lets you make an attack action during a power action. So, putting these 2 together, could a Transporter equipped with Double Time double their movement on a move & attack action?

Nope. Double-Time specifically states you cannot make an attack when using the FEAT.

Also, you cannot use either Double-Time OR the Transporter Move and Attack option if you start adjacent to an enemy figure.

And just on a technical note...the Transporter move/attack option is performed during a move action, not power action. And it allows a close or ranged combat attack (not action) as a free action.

At -2 AV, do you think the move/attack action is worth it?

Yeah it is! When Moonstar lost her Running Shot, the run by attack gave something useful to do. Sure she missed most of the time, but it was still good.

are there any feat cards to compensate for the -2 penalty on move/attack?

In contact with Oracle is a FEAT to help compensate.

Perplex always works too.

Is -2 good.... of course not but have you seen Vet hawkeye? 10 movement with an 11 attack (so a 9) with 3 damage and rce. 10 range and 3 targets. Just got this guy the other day and at 84 points i have to say he is going to be on a bunch of my new teams

Dont forget also when using the transporter attack option you can not use in powers, so no Phasing on lockjaw, etc...

So dont do what I did have lockjaw carry around Nebula, and set lockjaw in hindering. Then when I wanted to make a transport attack I was at 6 movement

Are there any powers you can use when employing the transporter move and attack option?

If you're going to be moving anyway, why not? I wouldn't plan my game around it succeeding, but it doesn't cost you anything to try it, and you could get lucky roll what you need despite the penalty.

My R Hawkeye at the pre-release had little trouble hitting figures with 15 & 16 defenses. Backed by the Scarlet Witch, his 7 attack (9, -2 for M&A option) was plenty to get an initial attack in. Then I'd park him and use his 9 attack + RCE.

Also if you have a Hydra or PD figure - as long as they aren't carried you can land a Transporter next to them and use their TA to boost the attack. With the large bases of these first few transporters you can easily get a 2 or even 3 Hydra/PD figs all adjacent on one attack.

Try it a few times, you'll see it has its advantages at certain times - just like every ability.

Try and get 5!