You need to have a heart to heart with this guy ASAP!!

$30,000 isn't exactly chump change. You need to go ahead and file liens on every project involved and only remove them as the invoices are paid. I would tell him you really don't want to, but you're very concerned that the money won't get paid and your lien rights will expire. He will either cough up some cash or tell you you're fired. If he fires you, he's probably doing you a favor. In that case hire an attorney that speciallizes in construction law to take care of the liens and notices to the project owners and lenders. You will get paid, unless that projects have already closed.