How about "I've been working with graphics for a long time
You are right, but hmm... time is "not defined", years are. I will need to think about.
Either go with "In addition, I have experience in many other areas, such as technology, computer science and marketing." or "In addition, I have experience in areas such as technology, computer science and marketing (among others)."
So "many other areas" or "( )" if I've got it right.
3. I feel that "with use of" works better with particular (and unique) things, rather than... variables. Would simple "using" be out of question or are you going for the "With use of this ancient artifact I was able to bend the forces of nature to my will" sort of vibe ?
I need to say that simple "using" was my first idea here, but "with use of" sounded little better - maybe because I like fantasy as you say? :D
"Multiple-page" requires a hyphen, I think. "Page" is not much of an adjective on its own...
"multiple page" solution was suggested by Tallima's post earlier. Hypen here would create "too long word" for me so maybe I should go back to original "multi-page" now?
"I have proof of that" - this is not a mystery novel. You have "credentials".
:D Sounds good but I've never seen that word in such sentence construction as mine.
"Cordially" belongs with words like "buńczucznie" and "krotochwilnie". It's cute and technically correct but... queer.
So how can you say "serdecznie"?
"I invite you" would be heck-of-a-lot smoother as "I encourage you".
Sounds better, indeed.
"familiarize yourself" sounds a bit patronizing; It kinda suggests that the reader is initially lost or confused. How about "browse" ?
It looks like nice solution.
"(...) with just
a small sampling" is pretty much "(...) z jedynie
niewielką częścią". Get rid of "just".
"In case of enquiries" "...break glass" xD How about "If you have any questions (...)" ?
It sounds really funny as you say. I will need to think about it.
"I invite you to take advantage of my services."
"Take advantage of" usually means either "scam" or "rape" (more or less) i.e.: "treat unfairly". You certainly don't want people doing that to you. Also - you've already told them to contact you a mere sentence ago. I think they got the idea ;P.
Hmm... I do not associate "take advantage" with "scam" or "rape"...