1)Does the home page sufficiently convince people to go further into the site?
I honestly thought for a moment you had sent me a broken link and I had been redirected to a google ad-page (those ones you find holding un-bought domain names). I have never been convinced to click on a google ad-sense advertisement, so my answer to question 1 is "no"
But, upon further inspection (and for the record I wouldn't have inspected it further if I'd happened to stumble across this page from somewhere on the Web), I did eventually notice some text on the left, and eventually realised the top links were navigation links. But in most cases it would've been too late, I'd have left pretty fast.
2)Does/can the site achieve its main purpose?
Can the site achieve it's purpose? Yes, it can, I generally got the idea of what you were about after reading through the pages. Does it do it effectively? Not really. Like I said, it looks like one of those advertisements... you really need to make the service you offer stand out from that google ad.
3)Navigation. Is it clear and easy to understand?
Refer to question 1. You should probably have some sort of header, and then a menu below it, because that is generally what people expect to see when they visit a web-site. Usually when I see links like that straight at the top of the page, it's on an advert, so my brain just ignores it. THe navigation really needs to pop out, whether it's through the use of graphics or colour/css, depends on what you prefer.
4)Appearance/Attractiveness
Refer to above questions. It looks like a google ad. It's a small site, so it doesn't need any big design implementations, but it's a bit
too simple. Like I said: the text and navigation
need to pop out and stand apart from that ad.
5)Images failing to load.
The only two images I saw were the page-rank graphics bars on the "Free pagerank display" page. If they are the only graphics, then no, nothing failed to load.
6)Search engine marketing. Can the pages be reasonably well indexed by search engines?
I'm not really an expert in the field, but it could be better I guess. You should probably make use of a few <h1> headings. Your title is interesting... how well it would attract a user searching for "free page rank services" or something similar, I really can't say.
In any case, the search term "page rank" or "check page rank" appears to be a highly competitive one. "Page rank" yields 216,000,000 results, whilst "check page rank" yields 46,000,000 results (

), so it's not going to be easy even remotely get close to the top.
Overall, the site needs something to hold the user's interest, and to distinguish it from the ad. Some colour/graphics usually fix that. Hell, you could even leave it all white, but just make it so it looks like a website, by using a page header, a little logo, some headings, and a clearly-defined menu. It would still be dull, but atleast people would know what it is
Anyway, I wish you all the best, keep at it
