Minerals and Heptavac together would be fine. Drench + vaccine not ideal but as you say you may need to do them together to minimise handling. If the ewes are generally fit and strong, then they should cope. I wouldn't vaccinate a ewe that was pulled down by fluke anyway - get the fluke treated and get some condition on her, and then Heptavac her.
Some farmers reckon that minerals + drench degrades the effect of one or both, and prefer to drench then give minerals a few days later, if practical. For one thing, it removes the load on her system of any fluke burden before you hit her with the vaccine. But be aware that if she had a very high fluke burden then she may get worse before she gets better - so don't vaccinate a ewe that is in poor condition and has gone downhill since fluking.
Some suppliers have tested and proven certain combinations of wormers, flukicides and minerals and you can buy combination drenches that include two or even three of those elements. Carrs, for instance, sell wormers and flukicides with minerals mixed in. The expiry date is much shorter than either product alone but they may be able to supply just a litre. Oh, and last time I used them, the minerals weren't chelated, so didn't give the longterm effect that a chelated drench would give.
Udders - she's going to lamb what she's going to lamb, and you'll check the milk supply both sides when she lambs, so there's not much benefit in checking udders at this point.
Feet - unless she can't walk / won't feed, she's better left alone and definitely not turned over at this stage. As ZtL says, give her feet an MoT after she's lambed.
Fluke - if you're in a flukey area and they're due a dose, then by all means fluke them.
Worms - generally ewes are wormed at or immediately after lambing, when any worms in their systems have woken up and the drench will knock them on the head. Then mums and lambs onto clean ground before the lambs start eating the grass.