OK, i was so stuck on level 2-10 but this actually works....
first, don't seat anyone until you have a full line of customers...if you stay at the podium while you do this, then they stay happy in line.....then, you pick and choose who you seat first...since seniors usually take more time to order, seat them first, followed by regular customers, and seat business women last.....this way, they are ready to order at the same time and you can get big bucks by chaining the entire resteraunt......drop off all food and hit the podium again and stay there until EVERYONE is done eating, then chain dropping off checks.....podium again to make sure everyone's happy and then clear all tables......stand at podium again before you seat everyone just to give them an extra "burst" of happiness....keep yer eye on their happiness level and if anyone's really unhappy, seat NO ONE and stand at the podium until they're happy enough that you don't have to worry about letting them wait a bit for something while you chain....or if you think they're gonna leave before you have time to make them happy with the podium, seat them first and bring them a tiki drink immediately, then seat everyone else...also, when resteraunt closes, and you have like 3 or 4 parties in the line, only clear enough tables to seat those 3 or 4 so that you can chain picking up dishes after those tables are done eating
this works in the upper levels also, and once yer in the third and fourth levels....in those levels, it's really important to keep an eye on their happiness levels in the line because the twist in these levels is that they've added crab legs in three and bread in four and if you don't bring it to them when they ask for it, their happiness drops.....crab legs and bread are a real pain and break your chains which loses so much money that it's impossible to meet goal, so i usually just ignore it which works as long as they're at close to full happiness when they're seated.....
this strategy seems to work with practice, even if you have to do a level two or three times to pass it, at least it works.....after i started doing this, i got to level 4-10 in a couple of days...hope it works for everyone else...good luck