The problem lays in the fact that my employer told me this week that he is not going to be able to pay me until January, due to some issues with the funding agency ...
The first thing you should do is verify the claim. As Ronald Reagan said, "Trust but verify".
I would like suggestion/tips about not burning any bridges with this current employer (mainly because I enjoy the current work, has a good work/life balance, interesting projects and lots of freedom), but also in order to avoid any issues for myself, such as not receiving the payment for these months.
About 15 years ago I worked for a small company that lost its Angel Investor. The owner of the company said similar things to keep me and the other engineers. He said he would pay us the back pay plus interest when he got a new investor. He also went so far to say the company was being restructured, we were getting shares in the new company, etc.
I worked for the guy another 4 months or so. I left after I learned the owner found additional funding but he did not pay us the back pay. He had enough money purchase himself a new Mercedes; and go to fund raisers and purchase autographed Baltimore Ravens footballs; but he could not pay us.
We did not get the promises in writing. I asked for the agreement in writing for several months over the water cooler informally, and through email. You can probably guess how that ended. It cost me about $60,000 USD.
The District Courthouse in Maryland has a legal aide center. I visited the center and the staff attorney told me tough luck because I did not have anything in writing.
The "have anything in writing" is an important litmus test. In my case, the owner of the company did not provide written agreement. In fact, he did not even mention it in email. If we emailed the owner about it, he would not reply. He spoke to us person-to-person.
Has your employer passed the communications litmus test? Has the owner put something in writing? If not, then I would be inclined to believe the statements your company are making are less than truthful, and may hide a lot of sharp edges.
Moving beyond the litmus test, you should get the exact terms in writing. This should not be offensive to the company. The company lawyers advise the company to do the same in its other relationships.
You should also insist the owner personally guarantee the agreement. It is possible the old company will be folded, a new company will be installed, and the IP transferred to the new company. With the old company out of business and the IP gone, there's nothing left to extract money from.
As an addendum, I'll tell you about a trick I now use due to the previous experience...
You need to have a record of a conversation, whether it is in writing or other medium. Purchase a portable recorder with some accessories to plug into a phone. I purchased a SONY ICD PX333 Digital Voice Recorder and Sony ECMPC60 Electric Condenser Microphone.
Call the person who is being evasive and not providing information in writing. Ask him/her to go over the details again for you. After the person speaks their first sentence, stop them and say, "I can't write as fast as you can talk", and then ask "do you mind if I keep a record of this conversation".
Your first statement disarms them and they believe you are taking written notes. The second statement is what gets you permission to record the conversation.
Some states don't require both parties to consent to recording a conversation. If you live in a state like that, then just record the conversation.
Also, from watching the Shark Tank, new investors don't want the old bills. If your company does get new funding, then the one thing I can assure you is there won't be any money for the past employee costs and back pay.
New investors don't pay old bills; rather they start fresh. Mark Cuban said the same on the Shark Tank. So don't believe for a minute a new investor is going to pay your back pay accrued before his/her agreement and investment took effect.