The photo ops and handshakes are over, the champagne has been carted away, and it’s time to get down to business.

Welcome to your first day on the job, Mr. Walsh. By the way, your team sucks.

You’re overseeing an organization that has become a laughingstock, with overpaid players that nobody wants, a coach whose team has quit on him and he on them, and only a couple of young players that could be considered building blocks for the future.

What’s weird about a situation this dire is that many of the decisions are really easy. Overhaul the team’s KGB-era press policy? Check. Stop giving jobs to players’ cousins? Done. Start taking phone calls for Eddy Curry and Zach Randolph? Absolutely. Buy out Jerome James? Done — and put that doughnut back.

Look beneath the obvious stuff, however, and there’s a whole layer of bigger-picture decisions that will be much more important in defining Walsh’s legacy with the Knicks. Unlike the decisions above, these ones aren’t necessarily easy. But because of that, they’re much more important. Here are four of the biggest:

What do with Stephon Marbury? At first, this seems obvious. Marbury might be the least popular teammate in the NBA, plus he’s indelibly associated with the failure of the Thomas era. Certainly an easy way to win points with the locals would be to tell Starbury to take a hike.

On the other hand, Marbury has a $22 million expiring contract. Think about that for a second. The Lakers were able to convert a $9 million expiring deal belonging to Kwame Brown into All-Star forward Pau Gasol. With Marbury’s huge, expiring deal, the Knicks would be a major player in any trade discussions involving star players over the summer or during next season. Throw in Malik Rose’s $7.6 million expiring deal, and Walsh could have a potential deal for two highly paid stars in a swap with one team. Of course, there are drawbacks. For starters, this is the way Isiah got into so much trouble, and Walsh strongly hinted during his press conference that he’d prefer not to go down that slippery slope. It would have to be a Gasol-type deal (as opposed to a Jalen Rose-type deal) to get Walsh interested — but isn’t it nice to have the option if such an opportunity comes up?

On the other hand, keeping Marbury’s contract around means keeping him in the locker room, and the Knicks might want to go ahead and start fumigating right away. Nonetheless, this is a much trickier decision than a lot of people believe, because the expiring deal is a potentially enormous asset. And how Walsh decides to play it relates directly to the next question.

How much importance does he place on 2010? The free-agent class of 2010 will include LeBron James and Dwyane Wade, among others, which means if the Knicks were able to get under the cap, it would set the table for them to poach James from the Cavs. (That is, if Jay-Z and the Nets don’t get him first).

In theory, this sounds highly appetizing. In practice, it’s not going to be that easy. For starters, there’s the little matter of getting under the cap by then — New York would have to trade Zach Randolph for certain, and would also have to do some serious belt-tightening this summer and next.

Second, the system is rigged against the Knicks. Most superstar players have a strong incentive to extend their contracts before they ever become free agents, and even when they do hit the market, the salary cap rules permit their former teams to offer the most money. In other words, it’s a high-risk, high-reward strategy. Maybe you get somebody such as James or Wade to come to the Big Apple, energize the Garden, and see Knicks basketball actually mean something again. Or maybe you become the post-Jordan Bulls, being awash in cap space but not finding anyone willing to take it.

What do with Isiah Thomas?

Ooh, that devious Isiah. Apparently he found a way to remain employed at the Garden, though in what capacity remains to be seen. Knicks fans are hoping the team treats him like Milton in “Office Space,” moving his office into a storage room in the basement, forcing him to do menial tasks (“Zeke? Donnie here. The toilets in the Felt Forum are backed up again…”), and conveniently forgetting to pay him.

But one can create two strong arguments against that approach. First of all, Milton ended up burning down the building, so that’s probably not a great omen. More importantly, this isn’t how Walsh wants to operate. His vision of the new Knicks is as a first-class, turnthe-other-cheek organization, rather than the petty, vindictive one they’ve been for at least the past half-decade.

Part of that vision means treating everyone with class. Even Isiah. So expect Thomas to get a fair hearing after the season instead of the Larry Brown treatment. After that, Walsh will gently remove him as coach, but allow him to maintain some kind of quasi-consultant title and perhaps offer his input on the draft.

Which young players are untouchable? The Knicks have a small core of young players — David Lee, Nate Robinson, and Renaldo Balkman, certainly, and possibly Wilson Chandler — who are potentially pieces of a much brighter future. Obviously, Lee is a little further along that path than Chandler, but all these guys fit the general picture of players who can contribute a lot more to a winning team in 2010 or 2011 than they can right now. For that reason, one might think they’re untradeable. But it gets tricky one you start looking at trades. We can say Lee is untouchable and the team needs to trade Randolph until we’re blue in the face, but the reality is that many teams won’t take on Randolph unless they can get a young star like Lee as part of the bargain.

These are the kinds of evaluations Walsh needs to be making, because nobody is going to take on the Knicks’ trash without exacting a price. Unfortunately, that price is likely to be one of their good young players, so don’t necessarily expect the Lee-Robinson-Balkman contingent to be here for the long term.

jhollinger@nysun.com