Basically what you are saying, is that it's hard for you to remember these words. Part of the fun of Scrabble is in expanding your vocabulary. Accept the challenge instead of limiting yourself. There's already a clear, concise Scrabble word list. Use it.
By the way, ETC* is not acceptable, because it's not a word--it's an abbreviation without its own pronunciation. Amp, ref, and ex are all commonly used English words, so I'm not sure why they offend you. How often do you really say "amperage" or "ampere" rather than amp?
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