Storyline Screencast Recording Sizes - Inserted into New Project

This regards my first real course simulation. We used to generate course simulations in Captivate, but have just moved over to Storyline. I have never recorded before so I am at a loss as to what would be normal sizes for recorded screencasts within a project.  I now have a SL project whose file size is about twice the size (70 MB) as our first project which has almost the same number of slides and same number of small audio clips.  They were recorded the same basic way except for two items;

1. The one project is one continuous recording; the large project contains four separate screencasts.
2. The original recording was recorded at the standard 720 x 540 px, the larger file was recorded at 1280 x 960 (still a 4:3 aspect ratio) but then inserted into a new project that had the SL size set for 720 x 540. We thought we would gain a clearer image and be able to read the field names and links better.  In our smaller resolution tests, this seemed to work.
3. One last difference:  The smaller project has a number of slides where the screencast object has been removed from the timeline.  Would this help reduce the overall project size?

My last question is what the inserted screencasts that are seen as "used" when inside a project under the Record Screen function in the Insert tab, are: are they "flv" or "swf" files?  What does Storyline create when we record from inside it to capture step-by-step screencasts and then insert in view, try, or test mode?

Thanks. I really do not think our LMS will accept a course that is 70MB in size although it does look like publishing it to an LMS will improve the quality of the images and screencast slides, while reducing the overall size.