A 371 Ask your DM.

Because the item description states that your alignment is "altered to an alignment as different as possible from the former alignment", your individual DM has the freedom to determine which former alignment is referenced. The Dungeon Master's Guide establishes that cursed items fall into three categories (page 272):
Cursed items are magic items with some sort of potentially negative impact. Sometimes they’re directly bad for the user; sometimes they’re just inconvenient. Occasionally they mix bad with good, forcing characters to make difficult choices.
An item which has only a positive impact (i.e., an effect that's directly in line with the user's wishes) does not fall into these categories. Thus your DM would be strictly within the RAW to turn the temporary alignment shift into a permanent selection by use of such a cursed item.

A 372 No.
If your charge attack hits, it deals an extra 35 points of damage.
War Leader's Charge uses the singular, so it adds extra damage to just one attack.