Where you go matters a lot if you want a tenured faculty position. It can matter less if you go into industry. I would still go to the best school you can get admitted to and funded at.
Most Phd students get either TA or RA positions. These typically pay tuition and provide a stipend. There are fellowships available, but these can be very competitive.
Graduate programs are more likely to fund you if you go for a PhD or a master's degree with a thesis. They generally fully cover the costs for a PhD program through grants and TA/RA position offers. Same for masters, but less likely; they fund PhD students before they fund MS students.
3.Probably not, you still have 3 more semesters to do research activities, take the GRE and IELTS/TOEFL, and get letters of recommendation. You should have all the application components ready 1 calendar year before you want to start the degree.
The higher the better, 3.55 is a good GPA but it also depends on the rest of your application. PhD programs have average GPA around 3.7 usually, MS programs are usually around 3.5 but it varies from school to school.
No, there are some bad ones out there, but most will do at least a reasonable job. The bigger issue is that different programs have different foci, from particular specializations to whether they feed academia or industry (and which industries they feed!). And while rankings do not always correspond with the quality of education, “better” schools will give you more opportunities to excel (and correspondingly better opportunities on graduation) even as they enforce a higher standard that will be too much for some.
Fellowships are financial aid with little or no strings attached, are offered only to top performers or applicants, and may, depending on the original source of the funding, be limited to citizens.
Assistantships cover expenses and tuition but require you to work in a lab, assist with teaching, or perform other “job” duties. They are usually offered without regard to citizenship and under wildly varying criteria. PhD students almost always have at least this level of funding in engineering, masters candidates may be eligible or may be excluded by department regulation, so if you are going for a masters make sure you understand your odds of funding at the departments in question.
Not really, but research experience can be a large factor and generally takes some time, so if you haven’t already, get involved! For everything else, you have plenty of time.
One of the advisors at my alma mater (ranked 25th or so) gave the following advice in regards to GPA and grad school:
3.50-4.00: Apply at top-5 departments
3.20-3.49: Apply at top-25 departments
2.90-3.19: Apply, but don’t be picky about rankings
2.00-2.89: Grad school is probably not realistic
He was non-specific at the time in regards to whether this means masters or PhD but in my experience these are realistic numbers for masters candidates and probably 0.2 low for PhD candidates.
Also bear in mind that while GPA is a large factor in grad admissions, it is not the only one - you will need letters of recommendation from professors who can speak to your research ability and/or potential, a good match with prospective advisors in the department, and other smaller factors like GRE scores. A 3.55 certainly positions you well for grad school unless you have your heart set on a PhD from a top-top-top program. And even then, you can always do a masters first and then transition to the PhD program if you perform well.