Need Help with Exporting Settings

Yes I have been doing all of that. My file size almost always goes over the 500MB. I am uploading to a Learning Management System (Cornerstone). The height and width are the max levels they support. The file size max is 500MB. The bitrate is the minimum accepted for that height and width. 6mbps will be too much, the file size will be too large. I have manually change the height and width as my webinars download in 1080p by default, so I change to match their standards. My video is 34 minutes long. 

Sorry to say that, but whoever placed these restrictions in place needs to revise them. Duration, Bitgrate and file size work together, if you can't make it happen you can't make it happen. Your process are not the problem, the restrictions are. Fixing the problem is better than adapting to it.

with a quick and rough test using your requirements (34 mins, SD resolution, datarate minimum of 2500kbps, Max size file 500MB) ...

is not possible.

The total file size I get for the above is estimated at 677MB.

The only way to reduce the file size to 500MB or below is for your datarate (kbps) is to be somewhere around 1700kbps.

It's possible that these rules you are applying did not take into account durations of this length? Maybe they were designed for shorter videos?

But in this case they just won't work. Either your duration is trimmed OR your minimum bitrate is reduced OR the file size is bigger. Something will have to give.

When you say you need to hit certain maximums, do you mean that you can't go over them? Is it mainly the file size? If you give reasons for this, advice can be more tailored to your requirements.

For now, I'll advise on settings that will give good quality. If you're uploading to YouTube, Vimeo or other places, the video will be re-encoded on that platform. You wnat yours to be at least high enough for that.

Export Settings

Format: H.264 (This is a standard for high quality videos output to mp4)
Preset: Match Source - High bitrate (You can start with this but then when you adjust settings, it will change to Custom.) There are many other presets, including recommended ones for Vimeo and YouTube.)

Basic Video Settings

You can keep the ones that match your source / sequence.

Bitrate Settings
Bitrate Encoding: VPR, 1 pass or 2 pass. (2 pass can give better quality. May be negligable. It takes longer to render.)

Target Bitrate and Maximum Bitrate (Mbps) can be set to appropriate levels. I find 6Mbps target and 8 MBps Maximum gives very good quality for most purposes. Could even be higher than needed depending on the source quality.

Once you change Target and Maximum, you will see an Estimated File Size at the bottom of the panel. You can change Target Bitrate to reduce that.

See the screenshot below.