Missing/rough idle and no power, blinking check engine light, stabilator light on when it is raining?

Hello, what exactly did they replace for tune up components? And if it was running well before the "tune up", they are responsible to right the concern. They obviously left some connectors loose or forgot to plug something back in. The blinking check engine light means the cylinder misfires are bad enough to damage the catalytic converter. So, I would bring it back and have them fix it before you end up with converters that are melted down.

If you don't have any way to pull codes, you can stop by AutoZone or Advance Auto and they can scan the PCM for free, write down all the codes, there will be misfire codes. If the issue is water related, and you have found water intrusion locations in the past, I would look for more, what might be happening is water is getting into the interior fuse panel or onto the Body Control module, these vehicles have a lot of issues with the BCMs, but if you're hunting down a water leak, you can have some run water over the vehicle with a hose while you're inside with a flash light, that's the best way to find a water leak. Thats what we would do in a shop.
If it's been 8 months, that's pretty long since the repairs. I'm sure if you added RTV at a location you're sure was leaking, especially at the pillar on the driver side, that's the location of the I/P fuse panel, if water was getting into that fuse panel there's possibly corrosion that builds up from moisture, corrosion grows inside fuse panels and wire insulation like mold.
So having someone else running a hose over the vehicle while you're inside is how you're going to find any potential water leaks.

I'd go see what codes are set in the engine computer first, if there's water or water had gotten into the fuse panel, it could have effected any number of circuits, check for corrosion in the fuse locations and the harness connectors that plug into the IP Fuse panel for corrosion, I believe there is a connector behind the driver side kick panel, down where your left foot would be, that kick panel comes off and there are usually one or more connectors behind there. Look into the connector pins for any white or green crusty corrosion, it will affect power to modules or components.

It sounds like you have more than one issue going on, the Traction light can be an ABS issue, and when you say "when at idle 5-6k" do you mean you mean 5,000-6,000 RPMs! Your engine should not be running at 7,000 RPMs, if your engine is really running at that high of an RPM and you're only going 30 MPH, that's a serious problem, maybe I'm misunderstanding what you're saying.

Okay, that sounds more like normal, 500-600 RPMs is a bit low for idle though. Can you look at live engine data with your scan tool?

Depending on where the Purge valve hose goes into the intake manifold, some of this could be related, if there's a leak in the Evap system then the system can be drawing in outside air when the purge valve is open, and that can be causing the fuel trim code. I believe that code is more related to a rear oxygen sensor voltage reading being stuck. I'm seeing a couple different definitions for that code.

Even though the P0442 is a small leak detected, I would check to see what the rear Oxygen sensors voltages are at to begin with. Fuel trim or air/fuel mixture codes can cause Catalytic converter failure if there's too much fuel entering the exhaust, it causes the converter to overheat and fail prematurely.

If that's what happened, being a flex fuel vehicle, it can handle E85, but it also has adaptive strategies for the amount of alcohol that is being introduced into the engine, I would stick with what you are doing now. The alcohol content can be reset via a scan tool, but if you have it running back to normal now, skip the E85 in the future. There will be a data PID in the engine data for the amount of alcohol, and in some cases resetting that is all a vehicle needs and that's probably where things went wrong here. Just keep filling it with non E85 and you should be okay. E85 is cheap because alcohol is cheap.

Here's some info on the Flex Fuel systems. I know fuel costs are very high in CA, compared to the rest of the states. Service info here explains that the Alcohol content is calculated through the Evap system and a virtual flex fuel sensor, so there is no alcohol content amount sensor anymore. So, allowing the vehicle to idle for a few minutes after refueling should help the system calculate the alcohol percentage. Another thing that I have seen is water in gas tanks, so if you're refueling at a station you don't normally use, it might be an issue with the storage tanks at that specific gas station. Because service info also states there should be no issue between switching back and forth between gas types as long as there is more than 3 gallons added (bottom of 1st diagram). So, you may have gotten some bad gas somewhere along the way, that's a very difficult diagnosis unless a fuel sample is taken and allowed to sit for a few minutes. The water and gas will separate.

As for looking for a vacuum leak, a smoke machine is the best way to start but finding Evap system leaks can also be very difficult. Especially when there is a small leak (0.02 in leak).
When smoke testing an Evap system you need to be careful, because most Evap systems max pressure when smoke testing is about 1psi, and the vent valve needs to be closed with a scan tool, so the system is sealed.
But depending on what codes are setting right now, this could all have been related. Since it's running better now, I'd be interested in knowing if any cylinder misfire codes are setting. The fuel trim code should have cleared on its own and been a history code, not current.
Most Evap systems have a test port with a Schrader valve that threads in opposite of a normal Schrader valve. This is one of the tools I use (4th diagram) when testing for Evap leaks, you'll notice on the green cap, it says 1 PSI max. But see what codes come back, you shouldnt have to reset the Alcohol content if the system is working correctly. A cylinder misfire might mess with that calculation.