Thank you for your email.
I shall try to respond to each question separately:
a) I have already been asked the question about employment in Dubai by an Engineer and my response is in the Advice section of www.emiratesgreeks.com, labelled Γενικές Πληροφορίες. I believe the same would apply to you.
b) Internet Recruitment sites - as mentioned in many of my postings, I do recommend them but would be selective in terms of type of employment. I was not aware of www.naukrigulf.com until you mentioned it. It appears they have recently opened up into the Middle East market, and as many others like them, I cannot vouch for their trustworthiness. www.bayt.com and www.monster.com are more established and I do recommend them. Yet, for Engineering positions, I cannot necessarily vouch for the range of opportunities - these sites are often used more for Administrative/Business/Office roles. A general rule of thumb is that if they charge you a fee for posting your CV or searching jobs, ask for too much personal information, etc., then do not use them. Otherwise, there is no risk in using as many sites as you like.
c) Again, as mentioned previously, the contract may or may not include accommodation/transport/etc. That really depends on the contract negotiation. General rule is if you are hired directly from abroad, these are included - if you are not, then there may be an allowance but this is often not enough to cover the cost. Check carefully!
d) There is no income tax whatsoever in the UAE - AT THIS TIME! Things can change without warning - eg. VAT is about to be introduced. You do need to check, though, with your own country's tax laws to ensure you do not have problems.
e) I cannot give you any idea on salary as it really depends on your level of qualification, seniority of experience, language skills, specialisation and other details. Also, it depends whether and what type of accommodation and transport, etc., is provided in the contract. A search on sites such as Salarysurvey.com can give you some guidelines but they are only general guidelines!
I hope this helps. Do let me know if I can be of further assistance.