Generally, you wouldn't hear * Osclaíonn mé*. I'm not aware of a dialect that consistently uses the first-person singular 100% of the time (that said, I'm not too familiar with the intricacies of Donegal Irish). I know parts of Connacht use it from time to time, but it's inconsistent and a change in progress.
Most of the time you'd hear * Osclaím instead, using the -íonn* form for all others (not counting dialects that still use the synthetic forms), which require the pronoun.
'Oscail mé' is in the imperative and as far as I know would translate as an order to 'open me'.