Thank you for requesting me by name:
1) It's "a" because you will be filing an I-130 for her that will give her an immediately available immigrant visa.
2) Yes, but I would not because you never know if emergency travel will be needed. Since it is free, she should do it (it is included in the price of the I-485).
3) If the marriage certificate legally changed her name to your last name, then fill everything out with your last name.
4) I would do one for $420 for the I-130 and one for $1070 for the I-485.
Please let me know if you have any additional questions as I will be happy to respond, but because this case is the type of case that I love to handle, I will now send you a low-cost offer so that I can pass on my personal phone number and email. I cannot discuss pricing on an open forum, but if you accept, you will see I have multiple services available to you from document review to full representation and all at very reasonable prices. You won't be disappointed as these are my favorite cases to do and have been doing them for many years. If you decline, no problem, you can ask additional questions without any additional charge. But PLEASE remember to leave a positive rating for me. You can do that by clicking on the 3rd, 4th or 5th stars if you see them, or the smiley faces if you see them. Also, a bonus is always appreciated if you feel I earned it. And finally, your question does NOT close just because you leave a positive rating. I can still answer additional questions for you without additional charge. Thank you for your understanding.