1) The local bus network Onda does have a fairly modern fleet but only some of there large buses have wheel chair lifts. The buses of the EVA/Frota Azul fleet that ply the inter-urban routes do not have lifts.
2) Some stretches of roads and pavements do have ramps but generally only those that have been upgraded in recent years. Bear in mind that many pavements are finished with "calcada" (Portuguese traditional stone pavemet) and not tar. This can give for an uneven surface where the calcada has not been relayed for a while.
3) Many (but not all) restaurants in the centre are on ground level with street level access. You would certainly have not problem getting into places like The Adega da Marina, O Algarvio, and several of the restaurants along Rua 25 de Abril in the centre.
