If you're missing, then your balance, position, and fatigue are all rising, worsening your chances of landing a successful strike. Use an easier technique.
Nothing has been changed with combat difficulty in the areas of position, balance, or fatigue (as far as calculations -- there was a message that was changed simply because it didn't make much sense, but none of the code was changed), so you must be doing something differently. Using a different weapon, have different burden/encumbrance level, using different techniques, different spells cast on you, etc.
Cure Serious Wounds doesn't exist -- assuming you mean Lesser Restoration, we can take it into consideration, but the real chances of us rearranging the spells again are slim. They seem to be working out quite well with respects to game balance and overall development. Clerics are the launch pad to a number of healing classes, including Druids, Paladins, Priests (to be released), and Healers and while they possess some beginning healing talent, it wouldn't make any sense for a base class to have healing abilities that rival those of of a Healer, for example.
Any wound that a cleric can't heal with Lesser Restoration, the NPC healers can (and do). They're free, you just need to walk up to them or be dragged in front of them and they'll work their magic.
As for combat strategy -- I'll leave that up to your fellow adventurers. Handing out strategy is not something we generally do.