Complex life in binary black hole - Sun(s) system
The Roche limit for a solar-mass (or 10-solar-mass) black hole is much larger than the Schwarzschild radius, or even the last stable orbit (which is a few times the Schwarzschild radius). So the Roche radius is a good limit (and, yes, you're right about the limit for an Earth-like planet and a 10-solar-mass BH.)

You needn't assume the BH has an accretion disk; I suspect most of the ones wandering around in our galaxy don't at the moment, just because accretion disks accrete (go into the black hole) over time, and so you only see them when there's some relatively recent source of gas to create the disk. (Most of the Milky Way black holes we know about are in close binaries, where the companion star is close to the Roche limit and is a regular source of gas.) Now, in principle the stellar wind(s) from the star(s) in your system could contribute to a very weak, tenuous accretion disk, but in practice it's unlikely to produce enough radiation to be of any concern, especially as you're assuming a planet with an atmosphere.

So there's no need to worry about whether or not the planet is tidally locked to the black hole, unless you want to specify the length of the day-night period. Of course, if the planet is only a few tenths of an AU away from the BH, it probably will be tidally locked before very long.

The variation in distance from the star(s) you suggest should be fine in "habitable zone" terms. In fact, given that the planet orbits the BH quite rapidly (about 1.3 days for a 0.05 AU orbit around a 10 solar-mass BH), it won't spend much time at either extreme, so you could probably have it go inside and outside of the formal habitable zone and still be habitable, as long as the average insolation is in the habitable range.  This would create some interesting day/night/seasonal effects, particularly in the tidally locked case: e.g., at a certain time of "year", the "eastern" hemisphere would experience noon when the stars were only 1.95 AU away, while for the "western" hemisphere noon would happen when the stars were 2.05 AU away. Half a year later, the situation would be reversed.

One last curiosity: assuming the black hole has an "average" spin, would it be realistic if the two Stars had a tilted orbit with respect to the black hole spinning axis?

That really depends on how the system formed in the first place. If the initial pre-BH star and the other star(s) formed from the same collapsing cloud, they would probably have similar spin and orbital angular momenta; if the spin of the BH is entirely inherited from its progenitor (which goes supernova to form the BH), then the orbital plane might be similar to the BH's spin. But if the system got put together later (maybe an encounter between a binary consisting of the BH and another star and the current binary pair, in which the BH's original companion star gets ejected), then the two stars could have a tilted orbit.