A heavy PA31 on a warm day has some interesting handling characteristics. Add in another factor - an engine hiccup, a short strip - and it is not a job for a beginner.
You are just describing a bad scenario for any light twin. Again manage your flight, if it's hot and performance suspect, limit the load or go with the noose light around your neck, your decision. Or just sit tight until conditions are better for that operation, then ask yourself why you let a s***box operator put you in such a situation, if you put yourself there, go on holiday for a few weeks and think about your life choices.
The Cheiftain is a very stable and easy to fly IFR platform, these days kitted out in many cases with better cockpit set ups than a lot of regional airliners. The PA-31 is simple, keep the speed up, don't get into the drag bucket, make sure your maintenance is kept up to spec. Read and follow the POH and you will be fine. Back when I flew them the insurance companies were not so phased and PPLs flew them around, a few bad endorsements and stupid hull losses, like the NNN event and so on and the insurers got touchy with all larger light aircraft. In the US PA31s are as much flown by private pilots as charter operators. Another way Oztranaughts make things out harder than they need to be and over complicate what is very simple. Learn to fly first properly and aircraft like the PA31 are a no brainer. No amount of ICUS will fix bad piloting and maintenance, which is how most of the accidents occur in these aircraft.
BTW I have flown these things in Charter and RPT many times at full load and flown more than a few minima circling approaches in actual conditions.
If you are going to have trouble with a PA31 you will have trouble with anything larger than a Cherokee,e specially big single pistons. And that said, I'm not saying you can jump straight from a Warrior to a PA31 and be comfortable, but from other light twins its pretty simple to step into. I did PA-44, PA-34 (I), and then into the Navajo, while I was nervous about the size I found it very easy to fly and stable so that IFR was very simple. Back then we did mixture cuts at 100ft on take-off and I've done actual feathered engine upper airwork in it, it was docile and performed fine to touchdown where we restarted. Also a Navajo glides better than a Lance with both engines feathered, but I won't go further into that. In any case I found the PA31 a pleasurable experience. There are however a whole book of myths and wives tales on how to operate it, some will lead you astray.