at the airport it is OK, just be aware that this reentry will not extend your stay, it will just give you the possibility to travel and come back within the initial 90 days given.
I wanted to send the link from MFA web page, but found out that they still use the file from march 2016, which is out of date. I have send a request to update, let's see if any use.
I close this topic, OP is advised to review his ideas. I do not want to be negative but the Thai Job market is brutal and with no special skills or experience this is going to fail. There are thousands of hard luck stories around, few successful ones.
border run to get 30 days you can do anywhere, Malasian are not limited by the TWO per year rule, as for Visa Run you could fly to Penang or KL to get a visa.