As far as lead versus featured, if an actor is billed above the title in the opening night playbill, then he/she will presumptively be considered for lead by the Tony committee (and those below the title are presumptively featured). The producers of a show have two weeks from opening night to petition the Tony committee in writing requesting that a given actor(s) be considered in categories differently from what their billing would indicate. The committee then takes it under advisement and announces their decision at a later date.
Producers often (though not always) get their way with these things. I remember that for "Fortunes's Fool" a few seasons ago, both Alan Bates and Frank Langella were billed above the title and as such would have been considered lead. The producers, fearing they might cancel each other out, requested Langella be placed in the featured category (while his role was smaller than Bates', it was still very much a leading role). The Tony committee agreed, and come Tony time they BOTH walked away with awards in their respective categories.
"What a story........ everything but the bloodhounds snappin' at her rear end." -- Birdie
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"The Devil Be Hittin' Me" -- Whitney