Editor said I may apply reviewer's suggestions and resubmit "if I wish", what are the consequences if I don't?
First, a reviewer can only make recommendations for revisions. The editor should make clear what changes should be made but it is still up to you if you see fit to do so. Of course, if an editor says you should make certain revisions and you do not, particularly without indicating any good reasons for not doing so, the risk is that rejection decisions may follow. From this point, you may see that providing good arguments why such revisions cannot be made are necessary. 

The fact that revisions take time is not by itself a good argument since it may mean your manuscript is currently sub-par but that is up to you to convince the editor when you submit your revisions. The revision process is in this case a sort of give and take process where any revision not made has to be clearly argued from a scientific point (not from a point of time constraints or other irrelevant aspect).

The comment you quote seems a bit lazy on the part of the editor because I think there should be additional qualifying statements indicating if any comments are more important than others and set the review(s) in perspective. How you should decide to respond is therefore hard to judge since the editor has, at least seemingly, not provided any guidance on what needs to be done. This, unfortunately, opens for decisions in any direction. Your experience with your field, should, however, provide some guidance for what should be expected of a study such as yours and also checking the standards of the journal should add some pieces to decipher what must be done. In the end, you will need to provide feedback on the reviewers comments that allows the editor to understand the scientific reasons and ramifications of your revisions (or lack thereof).