Alright lets see. First off, you normally don't want 2 moves of the same type on a poke. There are a few exceptions, like when one move has a special trait or ability, but most of the time it's a no no. If this is your E4 team, i would suggest removing all HM moves, save surf and fly, as you're not using any HMs in the E4, and they're weak attacks that are wasting a move slot.
First on Empoleon, i would swap out rock climb for Ice Beam, for pesky dragon types, which you already resist. And also get rid of brine for Agility as empoleon's speed isn't the greatest. After one agility, you have a realistic chance at outspeeding a fair few pokemon. If this is your E4 team, i would suggest removing all HM moves, save surf and fly, as you're not using any HMs in the E4, and they're weak attacks that are wasting a move slot. I suggest replacing sunny day and solar beam on Roserade with leaf storm or petal dance eventually, i understand you can't right now due to level.
I would probably replace bastiodon with a fire or fighting type, as you can use hippowdon as a physical wall, and they share similar type coverage. Preferably fighting type as you lack normal/dark/steel coverage save EQ on hippowdon which only covers certain steel types. Lucario, Infernape, Blazekin, Medicham, Magmortar, and many others would fill that slot nicely. Let me know which you choose and i'll give you a set for them.
i would replace thunder on frosslass with shadow ball, it's a very good STAB attack, and thunder is inaccurate except in rain. Also i would get rid of blizzard/hail or ice beam depending on how you play. you really dont need both, so it's up to you as to whether you'd rather have the evasion bonus from hail and the 5 uses of 100% accuracy base 120 attack, or ice beam's base 90(?) and 2 extra move slots. You could even leave hail for the damage over time and evasion bonus and get rid of blizzard for another attack, maybe destiny bond, but you really dont need both. However, with levels, frosslass could easily sweep lance by herself with hail/blizzard or even ice beam if EV'd right.
Honchkrow i went Fly and Night Slash for STAB, Steel wing for coverage on rock and ice which would otherwise give you trouble. Faint attack for double teamers, but that last attack is really filler. use whatever you choose.
Hippopwdon looks ok, he's not really meant to be a sweeper, but he can be a good hard hitting wall. Personally i would swap strength since it's an hm move, and crunch as it's SE on psychic and ghost, both which are normally SpAtks which you dont want hippowdon up agaisnt if you can help it anyways. I would use Hippo as a lead, with Stealth rocks and Roar, then EQ and Yawn. Start off the match with Stealth Rock, and sandstorm will help build passive damage. Then use yawn, and roar if necessary, and you can really rack up the passive damage.
As far as EVs go, I would go with Atk/Speed on Honchkrow. SpAtk and speed on Roserade. Empoleon is really meant to be more of a special wall than a sweeper, but it can still do decent damage. And with a Naive Nature, i guess you could try Speed and Sp Atk also. though most people say HP/SpAtk. Frosslass has decent speed naturally so i would invest in SpAtk and then a mix between speed and HP depending on your IVs. Your fighting/fire type i'll let you know when you choose one, and for hippo I would go EVs for HP/Def since you have an adamant nature. you can toss some into spDef if you would like also, but meh.
I know it was long, but i hate waiting for replies on my stuff too so i figured i'd do what i can
GL and let me know if you have any questions.
