Any body weight.

I say 225 pounds is good 'nuff because most most men could do it without training but would hurt themselves or the soreness level after the lift would render them unable to do any other sports effectively for a few days. I would expect a novice dead-lifter to be able to hoist 235 pounds at a body weight of 148 pounds. You don't need to be any higher than novice unless you really want to be. It gets bloody addictive though so watch out.

For the bench press I would say between 135 and 205 pounds is good 'nuff for a man of any body weight. Many triathletes, because of the swim, will probably find themselves into this range fairly rapidly. Distance runners have trouble here because for many of them this will be the first time they are truly activating those muscles. As a personal aside, when I was 168 pounds I was bench-pressing in the 280 pound range when I thought that beach muscles were the most important thing in life.

For the hack squat and squat I would say between 225 to 250 pounds is good 'nuff for a man of any body weight. For many triathletes and runners this is probably not going to be seriously challenging, even if it does people tend to go from novice to intermediate quickly in squats, the body responds very well to them.

I did this analysis based on the idea that the athlete would be engaging in multi-sport activities between olympic distance and half-ironman distance races as the primary focus of the athlete. If it isn't then advanced dead-lifting for a man of 148 pounds is 380 pounds so you can see that unless you are extremely light then body weight in this discussion isn't quite that important.

Two times a week on an olympic lift is plenty to maintain. In fact, a lot of guys will only do squat one time a week and when the next leg workout comes around they will do other leg exercises. The squat and DL are lifts that, when done correctly at 98-100% of max, shouldn't be attempted again for 4-5 days afterwards. If one muscle system (lower back, upper back, quads, glutes, traps) is fatigued too much the resulting poor form that could accompany that is dangerous when you are playing with heavy weight.

@stop2think: People progress on the DL and squat fairly quickly, it is not a surprise to me at all that your wife can DL 225 pounds. I bet if I saw her in a tank top I would notice her trapezium muscle was better defined than most women's.