Oh, I think I see! So basically Kyuubi has a given set of abilities that Kushina in canon can access by virtue of the fact that he's sealed inside her, and so you'd like to know if, for the purposes of this fight, she can access those Kyuubi-abilities even though at her current canonpoint she doesn't technically have Kyuubi inside of her?

If that's the case, then the answer is yes, she can! Mind you, Kyuubi won't really be inside of her, but she can feel as though he is (in that sort of strange dreamlike way where you just sort of "know" something even though you have no proof of it), and she can access those abilities that she would've had available to her while the Kyuubi was inside of her. This will NOT present a multiple drain on her dream battery because, as mentioned, she's not actually summoning Kyuubi to reside in her and then trying to use its abilities; she's just recreating them out of existing dream juice, if that makes sense.

As for your third question, it's plausible that she could hold him down long enough for people to get a few solid hits in! He'll break free relatively quickly, though, and she'll need to chain him again (which, obviously, will take further effort and so on).