Transparent wrapper class for data structure in Python
Correctness?

I copied your code, and added the following testcase.

if __name__ == "__main__":
    k = ResizableDeque(maxlen=10)
    k.append(12)
    print(k)
    k.maxlen = 10
    k.append(13)
    k += [14]
    print(k)


Expected result:

deque([12], maxlen=10)
deque([12, 13, 14], maxlen=10)


But I got

deque([12], maxlen=10)
deque([12, 14], maxlen=10)


The reason is that you copy over a bunch of items in __init__, but not in the maxlen.setter.

Whitelisting vs blacklisting

In __init__ you copy several items over using a skip_list. Why not explicitly define the items you want to copy over instead?

Actually, why copy at all? Performance would be a proper reason, but then I'd suggest copying just the items that have proven to be necessary to copy (after profiling).