Sorry it's been a while. Been pretty busy. Then sick. Now recovering from sickness = time + energy enough to view interwebs.
8.3.3 There is an unnecessary carriage return after the description (before 8.3.3.1). The description itself is perfect, though.
8.3.3.1 If it's a throw (and does half damage even when completely blocked), I assume you don't skip straight to the reversal step. Is this clearly enough implied, or should there be a note or subrule here?
8.3.3.2 This should include a "(rounded up)" bit after "half damage". (I know 8.3.3.9 sorta covers it, but 8.3.3.9 appears after Damage Adjusters, and seems to be talking about final values. Adding it here will make it clear that values are rounded up whenever they are halved. It's technically unnecessary, but it keeps folks from having to hold decimals in their heads for more than one step.)
8.3.3.6 There is an extra space before "The active". I.e., the "The" in 8.3.3.6 is a bit to the right of the "Phrases" in 8.3.3.5.
8.3.3.8 "Subtract the appropriate amount" is a pretty vague phrase. Perhaps this should say, "Subtract the final damage amount".
8.3.3.10 "a vitality loss of at least 1 or more" is redundant. This should either say, "a vitality loss of at least 1" or "a vitality loss of 1 or more".
8.3.3.12.1 This isn't bad. I definitely can't think of a better way to put this. Good addition.
8.3.3.12.2 This doesn't really make clear whether the multiple copies are part of the current attack, or the current attack resolves before the attack sequence for the first multiple copy begins. I suggest following the parenthetical with ", this attack resolves." Then start a new sentence with "Begin a new attack sequence". There are just too many old cards that respond to an attack "resolving" to leave this unclear. There should maybe also be something about whether the multiple copies are considered part of the current form or not? I.e., when does the form resolve?
8.3.3.12.3 Should "combat phase" be capitalized?
8.3.4 As noted elsewhere, something in here should describe how attacks played "as reversals" work. Do they get the Reversal keyword? Is it played? Can it be negated? If it doesn't get the keyword, when in the Reversal Step can a card be played "as a reversal"?
8.3.4.3 As with 8.3.3.12.2, this doesn't really make clear whether the Reversal's attack sequence is part of the current attack, or if the current attack resolves before the reversal's attack sequence begins. I suggest replacing "will initiate a new attack sequence." with "will resolve the current attack and initiate a new attack sequence." There are just too many old cards that respond to an attack "resolving" to leave this unclear. Same reasons. Also maybe something about whether the reversals are considered part of the current form or not?
8.3.4.4 I suggest following "multiple copies" with "(or similar additional attacks)" to make it clear for abilities that aren't multiples, but are functionally similar.
8.3.4.5 I suggest adding one additional clause. Consider following "the attack sequence is ended," with "the attack is considered resolved,".
8.3.4.6 Shouldn't this say, "The Reversal keyword ability is a Response," and "If a Reversal keyword ability is negated," ? A Reversal is either an ability or an attack _with_ that ability. You can negate the ability (which lets you play the attack), but not the attack itself, generally. Yes/no?