I find Monarch to be easy and play with raging barbs, aggressive civs, no tech trading and permanent alliances to make it a bit harder.
I do this because I currently struggle on emperor and don't enjoy playing this level.
I also play marathon and either large or huge maps.
I wouldn't play random leaders initially as it is harder than playing with a leader that you are used to.
The charismatic trait is excellent and with financial and a good UU, Hannibal is an excellent choice.
Maybe switch off barbs initially too?
I wouldn't restrict yourself to a set build queue as it should depend on the terrain though a worker 95% of the time should be 1st unless there are fishing resources and you start with the fishing tech. I would research hunting and archery before 2900 to allow the production of archers before the barbs appear. Bronze working and animal husbandry are also important. Get pottery and build cottages on grassland and floodplain tiles. Remember to only expand when you can defend your cities with an archer, try and build improvements that you can defend also. Warriors with the woodsman 2 promo can be excellent initially also, but they are crap at defending cities. Barbs are also more intelligent and seem to coordinate attacks in Warlords.
You want copper and horses - I go for archery because I hate building on top of a resource (probably my failing on emperor).
You also want your 1st built settler around 2500 or earlier + an archer.
Build stonehenge in your capital (need for culture) after building your 1st settler and chop the forests - I then like to research the religious techs and then build the oracle.
The priest GP produced is then used to get Theology and Christianity. A shrine is a big boost.
I will use the oracle to either get - code of laws if failed to build stonehenge, monarchy if there is lots of wine, but usually use it for metal casting - early forges especially if gold, gems or silver is about.
My 3rd city I aim to get before 1500bc.
The new cities either build settlers or workers or archers depending on requirement.
I then may build another 1 or 2 depending, but no more. I am then looking to build barracks in my cities - I then fill the build queues with axemen, chariots, swordsmen and archers, change to theocracy and pump them out. Change back to organised and build missionaries, monasteries, temples and libraries.
I then use my newly created small force to take any barb cities, normally raze them (unless on a good site) and I then look at a small war with a neighbour, good for experience, great general points and to pick up a couple of cities with no defence bonus.
I will use the build queue tactic all through the game (normally switching between pacifism and caste with theocracy and vasselage) - next is when I can build cats (elephants are great) Then I am looking at a major war with a neighbour. I will do this again before macemen and will do again when macemen come along - each time before going to war.
Expansion by war makes the game easy as the AI is piss poor at war (don't be scared if the AI strength is higher than yours), though protective trait AIs need to be given respect. i find the early barbs razing my improvements are more of a problem.
I also hate to lose units, apart from cats, and I will build up a strong, promo rich army heavily dependant on city raider promos for melee units and combat promos and the 25% bonus promos for chariots, horses and elephants (though flanking is useful too). I never attack or move where it would leave a good promo unit vulnerable (the +1 vis for a cavalry unit is great).
Don't waste time on medic promos as many short sharp wars are the daddy, make peace when you lose momentum. If you are in a war too long, you will lose ground on other civs on other continents.
I few of the things I normally do off the top of my head as I am bored at work

I do remain flexible though depending on the situation and the above is just what I like to do and I find it works on Monarch.
I never generally have problems building any wonders that I want and I want them all! Chop, Chop, Chop, Chop. (stonehenge, oracle, parthenon, great library, colossus are the early ones I like to get, I then make sure I get statue of liberty). Also build the 2 great epics as soon as possible in the best for purpose cities - GP farm and unit farm. (I tend to find the game a lot easier if my capital is suited to be a GP farm even though this reduces the power of buearocracy (spelling

).
Cash for upgrades is also essential, get a great merchant and send him to the biggest AI city with open borders.