Hi there. Any help regarding my current situation would be greatly appreciated.
I am 35 years old and have been teaching in Thailand for the last 4 years. Following a trip home over the summer and the collection of a new passport (old one was full), I changed schools at the start of the academic year. Through the schools inexperience in applying for foreign teacher work permits (or so they say), I have been sent to the Thai embassy in Laos three times in the first term.
The first time I received a non-immigrant B visa but the school didn't do what they needed to do in applying for my work permit on time. So, with just a day remaining on my visa I had to return to Laos, but was unsuccessful in getting another immigrant B and had to return to Thailand on a tourist visa. The school sent me back again two weeks ago but yet again I could only return on a tourist visa. The immigration officer at Vientiane who I had spoken with each time I was there, told me the school were not handling my application correctly and that they could no nothing to help, though he seemed genuinely sympathetic.
I've since left the school and I'm going home for two weeks (a holiday booked prior to leaving the school). I intend to return to Thailand as it's where I'm set up, but I'm concerned as my new passport is now almost half full of entry and exit stamps as well as three Laos visas, one Immigrant B visa, and two consecutive tourist visas. I was thinking of trying to get a new passport while at home and starting fresh that way as I'd like to take a break from teaching until the next academic year. I have an income from some online freelance work from my home country so I can sustain myself. What I hope to do is come back through BKK on the 30 day visa, and if possible, get two consecutive tourist visas from Laos. From there I would apply for work at a new school.
Should I go ahead and get a new passport? Would that sort it? Or do you think I could get more visas on my current passport? Is there another option?
If anyone has had similar problems or knows the ins and outs of this and can offer some advice, I'd greatly appreciate it. Thanks in advance.

No harm in getting a new passport and if current one is already half full in less than a year sounds like a good idea - but you really should arrive with at least a single entry tourist visa (or two or three if you can get) as flight may be a problem without a visa and no onward ticket within 30 days.

I have been in your situation many times, schools not providing correct documents for Non B for teaching.

Tourist visas in between. How many more tourist visas will they give us, while most were meant to tie us over until the school had the docs. Nearly 4 years teaching now.

You could go ahead and fill up the old passport or as Lopburi suggests get a new one.

The previous visas are all on file at the respective consulates although they will not appear in your new passport.

I have sure gotten to know that guy in Vientiane who has the final word with your application before it goes inside for you to pay for it. There always seems to be some new document that is necessary that we are not aware of. Last week a poster recounted his no Non B visa experience, some document, a letter from the head of the Labour Office to go along with the receipt for the W.P. This is new to me, as was the teachers waiver, until last year.

Apply for a double entry tourist visa when your are in your home country

No need to get a new passport unless it is a last resort