How can I land a PA-44 (Seminole)?
I have some time in a Seminole.  The issue with twins that causes most of the difficulty is the speed brake effect of two propellers when you pull the power off and they go to full fine pitch.  It's like you deployed a couple of drogue chutes, and makes your speed decay very rapidly and you will find yourself sinking quickly and needing large pitch inputs to try to arrest the sink, and with the Seminole's pitch behaviour this can be challenging to master.

The Seminole is not helped by having fairly high stabilator forces in pitch in the flare, and the T tail causes changes in stabilator effectiveness and sensitivity as the surface comes down into the wing's downwash during the pitch up.  

You should be trimmed for hands off flight at your final approach speed (you trim to a speed - think of the trim wheel as your hands-off cruise control speed select dial) 90kts if near GW, 80kts when light.  Some pilots feed in a little bit of extra NU trim just before the flare to reduce the pitch effort, but this puts your trim speed even slower, and if you go around, you will be frantically spinning it ND and pushing on the column as you accelerate to blue line - more so than if you were trimmed at Vref.

Your aim point is 3-500 feet down the runway (in big aircraft it's 1000 ft).  The numbers will do fine as a reference. Your target condition is, as you are passing down below 300 ft or so, you should be trimmed with power set so you can let go of the controls and the plane will hold speed and track the glide slope without any input from you.  Then it's little nudges and small power changes to correct things.  The key is trim to hands off on-speed and on-slope so that the airplane works with you, not against you. For your questions:


Don't rely too much on crutches like standard clearances from objects in the cockpit.  Your target is to have the touchdown zone simply staying in the same spot in the windshield as you close in on it, wherever that spot is.  The "two fingers this, three fingers that" varies with loading so can't be used except as a very general reference for starting out.
In a twin like that you carry power through the round out and the start of the flare and you settle into ground effect. For starters, just leave approach power on until you are at about 5 feet then pull it to idle as you are feeling for the runway.  With experience you can work on feathering the power off from a bit higher up, getting to idle just before touchdown, but it's too much to think about early on.  When you want to make small or slow power reductions, it's easier to manage it by walking the levers in little alternating increments by rotating your hand.
The hard pull for the flare is characteristic of the Seminole and is just something you have to get used to.  As I said, you can trim to a slower speed during the round out to reduce how hard you have to pull, but if you do a go around you find yourself trimmed for, say, 65kt and as it wants to accelerate you will be pushing pretty hard on the wheel to keep the nose down to accelerate to blue line while frantically reaching for trim wheel.  Then if an engine quits and you are distracted doing the drill without retrimming, while holding a hard forward push, you will inevitably let it relax, and things go south.


The biggest factor that will help with your flying is mastering the use of trim for managing speed (it gets more complicated later because you pitch to speed when flying visually, but later when doing instrument approaches you pitch to slope because you have to maintain a precise path on a little needle - worry about that later).  You never want to be holding continuous pitch pressures for any more than short transient conditions.  You don't crank the trim wheel to make pitch changes (although you can) you make pitch changes and follow up with trim. This gets more and more important as the planes get heavier and the control forces go up.

Large turboprops are flown with power right up to the touchdown.  Jets come off the power a bit sooner, and jets that are clean in landing config (generally those without slats) come off the power quite early - in the CRJ200, you go to idle at 50ft.