Re: How long is milk good for once warmed?
don't worry mama! it will all work out. when you are away from her, she will almost certainly take the bottle. and almost certainly it'll be easier for someone else to give it to her - sometimes babies even know when you're in the house vs actually away. the transition will take some getting used to, for both of you, but you can do it. and she will be ok. at 4 months she might be able to take from a cup, too, if she's really refusing the bottles.
i don't know about the cutting the nipple off ... seems like that would be more likely to lead to problems with her latch, than to actually help out with the bottle problem.
Nursing, pumping, cloth-diapering, babywearing, working professor mama with the awesomest SAHD ever.