A couple of things:
I don't know if stssn meant this or I misinterpreted but all the voters of Calvert County would not vote on the creation of a municipality, just those living within and registered to vote in the proposed municipality boundaries.
TAXES:
If a municipality is formed your overall property taxes would probably go up. That would depend on the level of services that would be provided. The property taxes paid to Calvert County would go down as a municipality has a differential applied to County taxes which lowers those. That is to take into account the services provided by the municipality which are no longer a County function (plowing and road maintenance for example, plus a bunch of others). And of course, property taxes are deductible.
The HOA fees would likely go away unless you have developments within the municpality that has them. Examples from the Beaches would be Burnt Oaks in North Beach and Richfield Station in Chesapeake Beach. Those HOA fees cover things like community property within the development, outdoor lighting on HOA property, parking lot maintenance, etc.
GRANTS:
To get a hard and fast number on those is difficult. North Beach in the last couple years has received Bond Bill funding (special state Legislature grants that are passed out. The state may be having difficulty this year but the Bond Bill money is still there) for the new Town Hall ($250K) and the redecking of the Boardwalk ($250K).
In addition, the Town has received grants from other agencies for a traffic and parking study, replacement of some problematic sewer lines, beach replenishment, study and redesign of the offshore breakwaters (one has sunk to below mean high tide), assessment of flooding and marsh degradation at the north end of Town, for costs associated with the Friday Farmer's market and some other smaller ones.
The Towns also receive State funding for Police and highways, although O'Malley cut that by 90% last year. Chesapeake Beach took about a $300K hit with that cut while North Beach's hit was about $100K.
A municipality also has an easier time getting reimbursed from FEMA and MEMA for natural disasters.
TAX BASE:
The State likes tourism for the various sales taxes, gas taxes, hotel taxes etc. involved. But don't think for a minute that tourism pays it's way in either Town. I know that's heresy so let me explain: Chesapeake Beach nets about $400K/year from the Water Park, a hotel tax from the Resort and Spa and about $500K-$750K/year from the amusement tax on the "slot" machines at the various locations. That's where the tourism money is coming from. If the Town didn't have those the take from tourism would be way smaller, a very, very small portion of the sales tax, the business license fees and the already in place property tax.
North Beach nets about $50K/year from beach and pier fees from non-residents. Again, it doesn't matter what business is in a building all that's received is a very small piece of sales tax and the business license fee plus the already there property tax.
The reality in most small MD municipalities is that a commercial base is at best a break even proposition for that municipality.
ZONING:
A municipality has it's own Zoning Code (in CB and NB the Planning Commissions are volunteer) so it's divorced from the County zoning. It can either be stricter, conform to or (subject to the overall State code) less restrictive the the County's. Until recently the height limit in North Beach for residences was less than in Chesapeake beach, although they just changed their's after that house collapsed last year. CB's commercial height limit is way higher than NB's.
BONDING:
As a municipality you would have bonding authority to incur long-term debt for things like road construction, stormwater management, basically any infrastructure. If I'm not mistaken you really don't have that ability currently as an HOA, hence the issues you have getting roadwork done.
MISC:
In a municipality if a property owner doesn't pay property taxes for two years the property goes to tax sale in May. If I'm not mistaken you guys have a large number of folks who are years behind in HOA fees and to collect those you have to have a lawyer file a civil suit in District Court.