If you think your positions in your mind without articulating them, then they don't count, even when it's a positive commitment. Also, 4 new mishnayot: betrothal via shaliach with conditions, like the location of betrothal. What if she has "vows," for example, as a lien, etc. She needed to be forthcoming monetarily. She needed to divulge any relevant details... or blemishes might be grounds for divorce (not as blemishes, but as undisclosed information). Plus, betrothal with less than the value of a perutah. Likewise, kiddushin for 2 women who are related in such a way as to prohibit kiddushin, via figs, plus they were shemitah produce.