Magzimum

You can use only one separator.
If the SRB is flopping around, and you need to attach it better, you can use struts. Best connect these from the booster towards the central tank.
If you need to eject the SRB with more force (that could be the 2nd reason you ask this), you can attach sepatrons to the SRB. If you put the sepatrons in the same stage as the separator, then will ignite at the same moment, and basically fly your SRB away from the central tank.
As DrLicor said, you can use docking ports to attach parts at multiple points, but I think that's far too complicated for your question regarding SRBs.

I recently posted my Eve adventure on the Mission reports. I experienced the exact same problem, and went through 5 designs before finally getting it.
I went with the inflatable heat shield below the engines. That still flipped because I had a few stabilizer fins that were sticking out... so I put some large fins all the way at the top of the rocket, with airbrakes (pitch and yaw enabled!).
The heat shield also would not let go of my rocket, even with parachutes semi-deployed. But once the parachutes were fully deployed and I slowed down to 8-9 m/s, it finally separated. But I used only parachutes to slow me down (no engines)... I guess you're going with an engine-assisted landing, since I see only 6 parachutes? I don't know if those parachutes will slow you down enough to get rid of that heatshield.
My advice would be to increase the number of parachutes, and to put them on radial decouplers (e.g. TT-38K), so you can ditch them before launching off Eve's surface. (Also makes for good fireworks, since obvioulsly used parachutes will detonate when they hit Eve's surface at anything over 12 m/s).
 

In my experience, the game can sometimes even throw your rovers/rockets around for no reason at all, even without time-warp. I've had a rover which was landed on Minmus safely, got parked (brakes on) and after I returned to it flipped itself into the air vacuum, as soon as the focus came onto it. Also I had a rocket which would shake itself apart on the launchpad, but only if I reverted back to launch... not if I loaded it from the VAB. Weird.
But physics warp makes everything WAY worse. Planes start shaking, rovers bounce. I use it with care, and I almost always press Quicksave before I turn on a physics warp, just in case.

Did your orbit have both apoapsis and periapsis above 70000 m altitude? (That is needed to count as "orbit", if the periapsis remained under 70k, even if your ship was in space, it is suborbital...).
Often the VIPs demand to get suborbital flight on Kerbin as well as orbit around Kerbin (and I guess the smart guys at mission control extort the VIP for a few extra funds for that suborbital "extra")... but the nice thing for you is that you can check the mission, and see if the "suborbital flight" already has a green check, but the "orbit" does not.
Other than that, these type of contracts are really easy. Take off, orbit, land safely, get paid.