Should I answer questions in order or skip around?

Skip around. Work from the questions you're most confident in to the ones you're least confident in, so that if you do run out of time, you run out on the questions least likely to produce correct answers.

Use the mark-and-review feature to manage this. On your first pass, solve only the questions where you see a clear, efficient path to an answer. Mark the borderline ones to revisit on your second pass. Leave the hardest ones as guesses.

For verbal, this might mean starting with the vocab-based questions (Text Completions and Sentence Equivalence) before tackling reading comprehension, then choosing which passages to read based on topic, length, or question type. For quant, it means scanning each question for about 30 seconds before deciding whether to solve it now, mark it for later, or guess and move on.