re why not unless...?
If merely gaining the ability to write scripts is your goal, your approach poses no problem at all. However, if building scripts that compile and appear to work (on a limited sample of data) is the extent of your ambition, you'll be missing a bet. One of the most highly valuable aspects of the Monastery is that you can call for help upon a community whose population includes some extraordinarily skilled programmers and whose topic is a wonderfully versatile language.
High level programmer skills go well beyond syntax.
If your data set is narrowly constrained, and you won't have to do too many s/// (where the value of "many" is "small" or "tolerable to you") that's a perfectly valid approach.
Answering that (for yourself; I can't without a better grasp of the data set) requires analysis:
- What are the elements in your data that must retain all UC form?
- Is retaining the UC form really required?
"Ltd." (mixed case with period/fullstop to denote abbreviation) seems quite as comprehensible as "LTD" -- unless your transformation is a step toward some other, later process which requires the form "LTD" (say, during the use of a program you can't modify).
As for the rest of your questions... go for it! I too tend to learn in exactly that mode.
However, as a favor to yourself AND to those who seek to help, please look hard at the preview of your posts for typos and/or language errors (for ex., "uncial" and "on" where "in" appears to be intended, above) that may obscure your meaning.