I run ultrabot 1.0 in Offensive mode with very few problems. Occasionally bot will run off in a direction endlessly until he is either killed by a mob, killed by falling, or gets stuck. This happens rarely but still annoying. More often the script will just end while fighting. I have not yet narrowed the problem down but it appears that the Xunleashed client is having problems connecting every once in a while which seems to cause problems with the scripts. Well back to my request... I run ultrabot in offensive with a Conjurer solo and pull with pet attack. Since the mobs do not come close to me I dont melee unless I am jumped. After looking through the script I noticed that there is a time limit on a fight and if out of melee range for a given time it moves on. This may or may not cause problems. Also if my life goes below the heal string check I start casting my pet heal even if pet life is full. This wastes precious power and makes the fight take much longer than necessary, often ending with me dead somewhere. We need a separate string for pet heals and player heals and have the check to see if it is our pet hurt or if it is the player. Also since pet is tanking away from the player looting is difficult since the toon stays out of range of looting. Perhaps have a way to move up to mob after engage using the distance check.
The second issue with your bot script ending is XU servers coming down, it seems they do not want scripts running without their servers online which gulls me to no end (my bots always die at this point which cause me 10min of re-setup time per bot) but they don't seem concerned. There is nothing you personally can do other than complain.
I also use the offensive mode with my necro however I learned along time ago due to mob roaming patterns pet pulling is not the optimal solution when using this bot. Not saying it can't be done, just I would not do it on any encounter that wasn't a stationary encounter. I (60 necro) always pull with a low lvl max distance DD spell with a 3 sec longer cast time than the spell says. I roam with max targetting set to 34 and have many waypoints all set to "0" so there is no standing around.
When I come to a waypoint it checks for mobs, locks on and casts the low damage DD spell to pull then waits 3 extra seconds and sends the pet (typ. tank pet in defensive mode) which casts a encounter AE DD spell and ALWAYS grabs the agro mobs (group or single). Now every now and again a mob slips thru and wacks me but I have more than enough HP to take a few hits while pet gains agro. I am not sure if your pets do the same type of taunt type actions but that is how I handle it.
As for pets and these bot programs both Slam666 and Rich are aware of the need for special pet performance controls (trust me I always mention it to them in mail) there are just several other priority ad-ons happening atm before that gets added in.
If you set up your bot to something similar (if your class's pet works like a necro pet) you should be able to heal your pet with little no no issues like your having now.
I hope this info. has helped some.
Loraik