As the Bay Area grasps for new ways to quell its affordable housing scarcity, a number of towns are contemplating controversial guidelines that would give some tenants a shot at acquiring their houses — a go that is sharply dividing house homeowners and renters. To avoid massive-pocketed buyers from scooping up houses, increasing rents and forcing tenants out, East Palo Alto, San Jose, Oakland and Berkeley are eyeing ordinances that would give renters, nonprofits or the city very first dibs on some gross sales. Acknowledged as prospect to order acts, the ordinances have been heralded by tenant legal rights advocates as a way to give renters a leg up in…