Here's a silly one: Did Luthien's ear shape change when she returned from Mandos to Middle-earth as a mortal? For that matter: were she and Beren resurrected in the same bodies or different ones? Was Beren's hand restored? Did they just awaken in Middle-earth or have to sail there from Mandos?
Most probably, they travelled to the Halls of Mandos in spirit only, while their bodies remained in Middle Earth.
The Elves don't actually have pointy ears. The difference between Elves and Men is almost entirely spiritual. The only physical differences are height (Elves are taller) and prettiness (Elves are much better looking than humans).
There are some references to elves having pointed ears in Tolkien's writing, but that's just a minor physical detail; the real difference between the two races is spiritual.
Geographically, I am bothered. If Middle Earth and Aman were connected by The Grinding Ice, why wouldn't the forces of the Valar use that path to make a surprise assault on Morgoth during the War of Wrath? Shouldn't that be an easier route to use?
Why didn't US forces in WWII just march across the polar icecap to Europe instead of using troopships? Same answer.
It's mentioned in the earlier sections of the text that the Helcaraxë is not exactly an easy trip. It's bitterly cold, lacks food(which they would thus have to take with them and baggage trains across fields of snow and ice are far more difficult to handle than supply ships amongst a convoy), it is effectively a constantly shifting glacier making any kind of reliable pre-planned route almost impossible, the terrain is constantly shifting and is implied to a be under regular, if not perpetual assault from snowstorms. The oversea journey, especially angelically enhanced for ease of passage was both faster and easier with much less risk of casualties along the way.
I know its mentioned somewhere that during the journey, many elves died along the way from being crushed beneath suddenly shifting ice. which made me picture it less as a glacier and more a densely pack group of icebergs, all constantly moving about. Its a mark of Fingolfins leadership that he brought as much of his host across as he did.
Besides, when you have Manwe the Vala of Fair Winds and Ulmo the Vala of Following Seas behind you, the sea passage ought to be pretty smooth.