This αει in ὅπως ἔχω τῷ τε ἀεὶ καλόν τι ὑμῶν ποιοῦντι διδόναι refers probably to didonai and not to poiounti.
in ordert to give always to one who benefits me in some way.
No. The αει is sandwiched within the τῷ … ποιοῦντι phrase, so it must go with ποιοῦντι and not with διδόναι, which falls outside it.
… ὅπως ἔχω τῷ τε ἀεὶ καλόν τι ὑμῶν ποιοῦντι διδόναι καὶ ὅπως, ἤν τις ὑμῶν τινος ἐνδεῖσθαι νομίσῃ, πρὸς ἐμὲ ἐλθὼν λάβῃ οὗ ἂν ἐνδεὴς τυγχάνῃ ὤν.
However, the position of the τε would normally imply an upcoming second limb of this ὂπως clause, contained within it. But then he changes tack and embarks on a new ὅπως clause, one with a different subject. Such structural imbalance gives the speech an air of spontaneity.
(P.S. I trust I don’t need to say that the οπως clauses are ordinary purpose clauses, with subjunctive.)
but if so there is a little problem translating aei as always. Would ‘each time’ do?
Yes, or “on any given occasion” or “from time to time” or the like. We met with this use of αει earlier I think, and I may have adduced ὁ ἀεὶ βασιλεύων.