When (not) to use diode/wired logic
The main problem with diode logic is slow rise time due to the (relatively) weak pull-up in combination with the ever-present stray capacity in your circuit (assuning a wired AND circuit). The use of a buffer transistor might get you into slow switching due to saturation. I don't think you will get into (addiotional) trouble from the less-than-perfect switching characteristics of your diode.

If you want to cut PCB size consider using some of the very small one-gate-per-package chips. OTOH, if you realy are a masochist, go for all the trouble you can find! But that does not match with asking here...

So impunity: NO. Check your timing margins, if you have a few us to spare I guess brew-it-yourself logic might work. Below 100ns I would not try it.