Your question of morality is interesting and I'll get to that in a moment, but I'd first like to share the experience in Australia where such a "First Home Buyers" scheme has been operating for some time. At one point it was AUD$21.000 if you were a first home buyer who built a home, I think at the moment it's "only" AUD$14.000. It started a few years ago at AUD$7.000.
From where I'm standing at the side-lines - I'm renting - it distorted the housing market in many unpredictable ways.
In essence it increased the price of all houses because the new builders would build a house with extras "for free", that incorporated the extra funding. Those first home buyers who didn't build got half the funding and that meant that existing home owners increased the value of their home by that amount so they could get the funding too.
Those same houses that were artificially increased in value caused a bubble in the price of housing, because the next owner saw the percentage increase in their area - as a result of the grant - and then they too wanted to see the same return on their investment, causing a self-feedback loop that made house prices increase like mad when really there was nothing to back that up. The result today is that the return on housing has in fact declined for the first time in decades - completely unheard of in most urban areas in the country.
The grant caused cases where the first home buyer was a child and many cases where people with extreme wealth found ways of getting the grant - for example, if the husband always bought their house as a company, then they could qualify for it as a private purchase etc.
By the examples I'm showing you might surmise that the grant brings out the worst in people. It goes directly to morality because it shows that when there is an opportunity to do wrong, a percentage of the population will in fact do so.
I don't think it's a good or sustainable means of stimulation, nor do I think it's appropriate to use aid that is not required. I think that shining the light on those who abuse the system will ultimately cause a return to common sense.
Those around me think it's appropriate to cheat on your taxes - for me, its the same thing. Ultimately you're cheating yourself and the society you are part of. Unemployment benefits, healthcare, education and infrastructure need to be paid for - even if I don't agree with all that is spent, that's the system I choose to be part of. Paying taxes is part of the responsibility that comes with being part of society - otherwise we'd be still living in caves, hunting and dying at age 22.
For me it's summarised in the following quote:
The ultimate result of shielding men from the effects of folly, is to fill the world with fools. --Herbert Spencer