It is not the best way to write a formal essay, (although I do that all the time!), kind of a shorthand form of writing but it does butcher the tenses somewhat....
It might be clearer if you break up the following phrases:
....using any and/or all the language.....
....are refined and/or processed,
...using any language, or all the languages ("and" here doesn't make sense), that is, it gives the students the flexibility to use any of the languages they know or (implied a combination of ) all the languages they know to communicate the activities... similarly,
...are refined and processed, are refined or processed ....
As for the second passage, "found a better dress-for less....", I think there may be a typo or spacing missing..."found a better dress - for less" which is better written (clearer) as "found a better dress, for less" (meaning she found a better dress that is cheaper). The "-" placed without spacing next to the dress makes it look like a "dress-for" which doesn't make sense.
Similarly, "most elusive of holy grails-an effective ...", if you insert a space or a comma after grails, it becomes easier to read as "most elusive of holy grails, an effective ...."
I assume you know what a holy grail is? http://www.merriam-webster.com/dictionary/holy%20grail