It sounds frustrating. One solution is to type your search somewhere else, in TextEdit or Word, for example. Then highlight it, cut it (Apple-X). Type Apple-F. Then paste it in (Apple-V).
That way Spotlight won't start searching for the first letter you type. Whether that way is better or not I don't know.
I'm pretty sure you'll start to see some free search programs coming out soon for people who don't like Spotlight.
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