Sorry for the length of this, but it brings up some interesting facts and possibilities.
The moons you mention, Titan, Europa, and Enceladus, are three very different places. Titan has a relatively large surface gravitational acceleration (as far as satellites go) and a very thick atmosphere; Europa has a relatively large surface gravitational acceleration and a very thin atmosphere; and Enceladus has a weak gravitational acceleration and a very thin atmosphere. This makes landing techniques different for the three.
At Titan the surface temperature is ~95 K (-180 C), and at the tropopause is ~77 K—really cold! And the surface atmospheric pressure is nearly 1.5 bars, for a mass density ~4 times that of Earth's. The gravitational acceleration is only ~1/7 of Earth's. I doubt that they would try to land on Titan with a BFR spaceship as currently envisioned. The cold, dense atmosphere makes for a tremendous convective cooling rate, so without prodigious heating many spacecraft parts would go below their allowable minimum temperatures, especially any exposed electronics and parts with lubricants. Handling the environment at Titan would require an extensive redesign. Titan's low gravity leads to a very large atmospheric scale height, the vertical distance over which the pressure changes by a factor of e. Couple that to the high surface pressure and you get an atmosphere that produces measurable aerodynamic drag nearly 1000 km above the surface (!), as Cassini and Huygens verified. When the hypersonic/supersonic deceleration phase is finished, there's still a long way to go to the surface, and that takes time. The Huygens probe took 2-1/2 hours to get down after opening its parachute, even with a change to a smaller 'chute on the way down. During that time the craft is exposed to even more intense convective cooling. That said, Titan's atmosphere and low gravity make aeronautics easy. It lets you glide most of the way down rather than having to burn precious propellants. As mentioned above, the duration of the part of the landing burn with the plumes impinging on the surface would be short enough that the amount of melting would be small. If the landing legs did indeed stick to the mostly-ice surface material, a quick blast of electrical or chemical heating on the pads would release them. There are all kinds of other options and issues to consider, such as: use of parachutes or a parafoil on the way down; use of a (really large!) balloon for the initial departure ascent so aerodynamic drag doesn't cost so much in ∆v; and use of rocket propulsion, or aerodynamics to land.
Europa's surface gravity is similar to Titan's, but its surface atmospheric pressure is 12 orders of magnitude smaller, so it's a vacuum landing. At such a low pressure the ice doesn't melt, it sublimates, going directly from solid to gas, so you can think of it as ablating. Again, the duration of the part of the landing burn with the plumes impinging on the surface would be short enough that the amount of ablation would be small. The main problem at Europa is the radiation intensity, far more intense (one to two orders of magnitude) than the Van Allen belts at Earth. The resolution of the image is too low for me to tell for sure, but it appears to show people (I assume in space suits!) with flashlights on the surface outside of the spacecraft. That's not going to happen! One other problem is the ∆V required for that mission, assuming it's not one-way. I suppose you could couple a cluster of big tanks to the BFR spaceship for the trip to Jupiter, Jupiter orbit insertion (maybe Ganymede and/or Callisto gravity assists helping there), pump-down to Europa approach (also with gravity assists), and Europa orbit insertion. Without the gravity assists the ∆V would be impossibly high, even with the auxiliary tanks. The tanks are separated and left in Europa orbit for the landing. Upon return from the surface the BFR would reconnect with the non-empty tanks for the flight back to Earth, necessarily involving more gravity assists. All this has to happen in a fairly short time or radiation spoils everything.
Enceladus is a much less demanding destination than Europa, except for doubling the heliocentric distance, which makes for long flight times (maybe in addition to the auxiliary propellant tanks you'd have some auxiliary food storage). The surface gravity is only 0.113 m/s^2, about 1/81 of Earth's, and the radiation is far more benign. Similar to the approach to Europa, upon arriving at Saturn and inserting into orbit (gravity assist or aerogravity assist from Titan?), you do a moderately ∆V-intensive pump-down to Enceladus approach and insertion into Enceladus orbit. But from there it's much easier: the total ∆V from a 100 km circular orbit to landing is only about 200 m/s. And the ice ablation situation is similar to that at Europa. Might Philae-style bouncing be a problem, landing in such low gravity with a big spacecraft? The south polar region is where all the action is, where the plumes are venting Enceladus's evaporated sea water into space, so that's the most attractive place to land. But with those plumes depositing thick layers of fluffy ice-grain material on the surface, it's hard to know what the surface topography is beneath the fluff, and that's a landing hazard.
This is a problem for all three destinations: finding the equivalent of a car parking lot to set down on. Titan would probably be the least risky in that regard, but you can't just set down anywhere. There are rugged mountain ranges, lakes and seas, river channels, etc. The only location where we know we could find a suitable landing spot is near the Huygens landing site. For Europa and Enceladus there are also rugged areas and other areas that look smooth and land-able at the resolution of the images we have. But the next level down in resolution might yield surprises, akin to what Armstrong and Aldrin found upon arriving at their Mare Tranquillitatis landing spot. And if you have fluff-filling of rugged terrain you can get other surprises, mostly unpleasant ones.
