One large problem I've run into in my personal journey is overemphasizing externals. I love saris and Indian food and Indian music, but that's not what Krsna is all about. To try and combat this, I'm trying to pare away pleasant trappings from what is essential.
An area of concern I'm having is regarding the language of ritual. Even for verses or invocations for which I know the English equivalent, when I recite it in Sanskrit or Tamil or whatever, I find it very difficult to concentrate on the meaning.
What I would like to know is if there is any leeway for performing private puja or rituals in the vernacular, or if it can only be done properly in Sanskrit?
In the "Arcana for Beginners" handbook there are almost no mantras in Sanskrit, and none in the puja section. Perhaps that could be of some help? For those who have received diksha, I personally think the mantras are important. They connect us to our tradition. Remember that Sanskrit is nobody's vernacular today, so everyone is in the same situation when it comes to learning them.
My first thoughts until someone better qualified answers: Krsna speaks (and understands) the language of love. GM told me (and is generally fond of saying) that the most important upacara, or item during the worship, is bhava (feeling).
If I am not mistaken, a brahmana at the time of the gosvamis used to worship one of the main Gaudiya deities but feel a very deep parental affection for him at the same time, so the food offering consisted in bringing the deity to the table to eat with the other children and wife; kind of like when we wait for GM to take the first bite and then we eat with him, as opposed to one servant tending to him and having his or her meal afterwards.
The mantras for the deity worship mean nothing but: "This is a seat, this is the offering, this is water to rinse off...", so you could, in the setting of a home, private ongoing worship, adjust the offering to better keep you focused on what it is you are doing: you could either say everything in English (well, not the mula mantras, etc) or you could just memorize what the words mean.
Personally I find it easier to say idam hastha-mukha-praksalanam than this-is-some-water-to-rinse-your-hands-and-mouth. In all honesty, when I was doing the morning puja I was just saying the mantras in my mind, but for the most part I kept my mind on the specific action (wiping the deity or whatever) and saying all those mantras at times was just getting in the way.
I think the point of the ritualistic worship is just this: keep your mind focused, because if you don't say a mantra at every object, you might slip into routine and just bathe, wipe, dress and feed the deity, while what goes on in your mind is more like: "Hmmm, I'm late today.... need to walk the dog... uh, and on my way I'll get the new issue of that magazine that comes out today... although really I should subscribe to the online version of it... I wonder if I got a reply to that email...."
Then again, you could say all the mantras, and that too could become part of a routine, so it all goes down to bhava seva.
In general it is best to discuss these details with the acarya, ritual has its importance, and alone, we might risk to adjust too much, or do away with some aspect of the puja that is really beneficial for the practitioner.
I'm "Indian bodied" and sanskrit isn't my vernacular either... curiously enough I do like to say the mantras and prayers in sanskrit. It's like my Latino classmate from Harvard Medical School said to me..."I still recite my rosary in Spanish. I feel God listens to me when I speak in Spanish." Since I was raised hearing the sanskrit mantras, I feel I'm connecting with Krsna, even if I bumble through reciting the mantras...
My new prayer I'm working on is the Sri Nrisimha Kavaca (even since a bat plagued my living room a few days ago). I've noticed that even after a few recitations, I'm getting faster and better. I also have a music recording which makes it much faster and easier to learn pronounciation. It also helps me to know how to chant the prayer in phrases, instead of word by word...
Hope this gives you some encouragement, if not, sorry to babble!