Here's a fun question: What would you rather your webcomic be, a rose or a wallflower? Roses are popular, make all of the top parties, and do well; wallflowers are shy, stay home, and don't really do well. Being a wallflower is easy; how do you become a rose?
You need to know how a search engine prioritizes the sites that it finds in order to fully appreciate the situation. When it comes down to it, there are four major criteria that determine how your site does in the rankings: Links, popularity, duration, and organization. Of these, organization is the most straight forward; the better your site is organized, the better your site will do in the rankings. Keep in mind that this also considers your meta tags (the more direct and appropriate the better; don't waste time on words in your description that just add words) and alt tags (those things that replace pictures for people that don't load images that they don't need), as well as any text that you put on the page. So, when you are designing your page, make sure that you use meta tags, alt tags, and text; search engines will love you for it.
Duration is something that you have no control over. Search engines look at how long your site has been around, and the longer it has been around, the better. When an SEO person talks about “sandbox”, he's referring to how long the site has been around, and will usual point out that it takes about six months for it to “get out of the sandbox” (most search engines want to make your site has been around before they rank it very high). Keep in mind that it also means that you should seriously debate completely re-doing your site, as it may put you back in the sandbox, and thus lower your ranking for a few months. As a side note, this also means that any changes to your site will usually take a few months to make any difference in the ranking.
Popularity is something that you can increase through successful marketing, and why you are debating link exchanges in the first place. The more uniques that your site gets, the better you do in the rankings. However, if your numbers suddenly spike and then go back to your previous uniques, the search engines will slam you; they don't like it when you play with your numbers, and a spike means that you are doing something interesting with your numbers. Therefore, you need to do something that increases your numbers slowly and surely, so that you don't set off any warning lights. This is the one area where link exchanges of any sort will definitely help you.
Links to your site are cool, with a caveat. In order to do you any good, links need to come from real sites and be of the same kind. Links from link farms (sites that have a large number of links going to a lot of practically random sites) are considered low quality, whereas links from sites that have something in common with yours are considered good links. So, linking to other webcomics and blogs about webcomic and forums about webcomics good, but linking to sites that sell Indian rugs are bad (unless your webcomic happens to be about Indian rugs, in which it's good).
What does this all mean for your comic? The sandbox will hurt you if you are constantly redesigning it, so design your site so you just have to change the images if you get bored with it and make it well-organized with meta tags and an alt tag for every image. Plug your comic as often as you can, creating backlinks to it. Debate link exchanges; if the sites are of the same kind (such as dealing with webcomics, or anime, or some common theme).
Design your site well, spread the URL in good soil, and your site will do better in the ratings. Do otherwise, and your site will be extremely lonely. Rose or wallflower, the choice is yours.