Hi Kc, glad to hear that Meteor Slides is working out well for you!
There is no option of "show all" for the slides, but you can certainly set your quantity to "99999" or some other very large number that will do nicely instead.
I'd caution against loading too many slides at once though. Depending on the number of slides, they could start to add up, causing the page with the slideshow to be several megs in size, which would really slow your site down.
How many you could comfortably load really depends on the file size of the slides, but it's something to keep in mind. I'd set it to some large but manageable number, like 30 or less.
The nice thing is that the slides work just like the posts in your blog, they are sorted chronologically. So if you are loading ten slides and add another, it will drop the oldest one and load that new slide. You can tweak the published date of your slides to rearrange them too.