We intentionally did not simply reproduce the gdb command set because while it does some common things in a very compact way, it has limited discoverability, and is hard to extend. The irregularity of the commands also makes it hard to provide good help & command completion. So the philosophy we took with lldb was to provide a logical command structure that used options explicitly, making it easy to combine them in complex ways and allowing the command completion to figure out what all the tokens should be, etc. While hard-core gdb fans were not fond of this decision, I have also heard from quite a number of folks that they appreciate the more regular and logical ordering of the commands.
Of course, we knew that that design would make very common commands awkward, so we built in a fairly powerful alias mechanism and added built in aliases for very common commands. These look like gdb commands on purpose, but somebody coming from another debugger could easily remove these and make up an accelerated command set they are comfortable with.
However, one other way to make command entry simple is to use the shortest unique completion for commands. So for instance, while having the command called "image look --type Point" makes it really clear what the command does (and makes it easy to provide a way to limit your type search), once you've used the command a few times, you'll probably end up typing:
(lldb) i loo -t Whatever
(lldb) i<TAB>loo<TAB>-t Whatever
In this case, it is unfortunate we couldn't think up a better word for "image load" since that makes us type three characters for "lookup", but since this is not such a common command clarity won over brevity... But as that instance illustrates, it is also important to leave as much of the command space clear in the basic installation so we don't make folks type more than they need to to get to commands, particularly any aliases they want to make for themselves. For instance, adding "info" to the base command set would mean that I would now have to type "im" not "i" for image lookup. So we try to avoid that sort of thing, especially if all it does is allow another way to get at extant commands.
As you are discovering, the alias mechanism (and the even more powerful one for Python command extensions) is not completely done yet. We need to add support for multi-word commands in the alias mechanism, Enrico's suggestion seems like a good one for that, and the Python command registration needs to be able to describe the command being added to the command interpreter so that we can do the parsing and command completion for it, making these commands equals to the built-in ones. That would be great work to have done if somebody has a little spare time on their hands...
Similarly, if somebody/somebodies who are so motivated want to come up with a more complete set of gdb aliases, it would be fine to include the results of that labor in the examples directory in the lldb sources for all to share. That way people who wanted to could easily include them, but we wouldn't litter the "first couple characters" command space for the common user.