I have been working with Roofstock for a bit, still have not had an offer accepted but have put in a few offers.

Check rentometer.com and see what is says.Better to wait for the right tenant than accept a sub par one that doesn't pay and tears up your place.

Or do I just disclose to the selling agent that I’m an investor and here’s my offer - if it’s accepted, I need X number of days to get secure the funding?

Bigger Pockets Family,I recently put in an offer on a deal in the midwest where I have another apartment building and it was accepted. 

Because we found out the home fell into this category (after our offer was accepted), and we were insistent that we wanted 2 income producing units, we began to solution for this issue. 

We just finished it a few weeks ago, and accepted an offer on it yesterday, Now we're finishing up the final touches on a remodel in Sunriver, that more than likely will be purchased for a Vacation Rental property by an investor, or a 2nd home.

I was looking at the big island because property is significantly cheaper, but so far have had no luck getting an offer accepted. 

All investing has some risk to it and if you can't accept that and do the right thing when something goes wrong then just keep your money in the bank.

I was nice, and we went to Goodwill together to try to find an item or two that had some sentimental value to her.Some people need to observe reality before they will accept it. 

We typically will have them prescreened with @Paul Ritter and MyCreditTeam.com prior to accepting them.