The return journey back to Europe and conclusion
[See post above.]
The retreat would be more chaotic for both fleets than the battles. Having left the French admirals alone, ships of the squadron previously involving Commerce de Paris were intercepted by the Spanish Navy and the British Mediterranean Fleet. Spain took a battleship of the line after it was shelled and staggered while the Royal Navy captured all frigates and surviving ships of the squadron off Toulon upon notification of the news. The actions took place in early May 1814 and were pointless, Napoleon having been forced to abdicate on the same day as the Toulon actions. [It was 11 May when these took place, he lasted several weeks longer in this scenario due to butterflies.]
After 3 May 1814, the last remnants of the French Navy's defeated Mediterranean Squadron fled back to Europe, numbering a single first rate [Austerlitz], the small battleship Breslaw, the 3 regular Temeraire class ships that set sail from Toulon [excluding a prize from the same class] and no frigates. At least the few brigs involved were detached before the convoy battles only to return to a defeated France if not captured first.
Unlike the 1st detachment, these ships were of the detachment that caused 4 ships to be wrecked off Jamaica before defeat and 2 more to be dismasted but saved, although both Spanish ships were among the wrecked and the British ships were later salvaged and returned home under heavy escort to deter American and French raiders from interception. Later, they returned to Brest on 11 July, safe from the British blockade due to the end of war and withdrawal of the Royal Navy as a result.
Most of the Royal Navy in the Americas was unable to intercept stragglers and retreating ships from both fleets as they were, after all, too busy getting the damaged and captured ships seaworthy for the voyage to Britain and fighting American ships and French privateers [the latter being unaware of the subsequent peace and recent defeat that occurred]. Although they were received with cheers at surviving and scoring initial victories, the heavy losses and Napoleon's defeat conspired to reduce celebrations along with Bourbon interference at Napoleonic supporters. Once the westernmost coordinates of European territory were reached by this second squadron of French ships, Napoleon's defeat and imprisonment became obvious to every British and Coalition fleet in Europe and this explained the safe arrival of the survivors into France.
Effectively, the Spanish ships were expandable in British eyes [non-British, 1st rate battleships but obsolete and disadvantageous with lower morale among the crew], leaving the French with no benefits against Britain but weakening a Spanish Navy and ironically, finishing the work of Trafalgar which involved them and saw them dismasted with heavy damage but escape. [The ships were Santa Ana and Principe de Asturias, having moved to Havana, Cuba in 1810 and were requisitioned in 1814 for British Caribbean duties.] Thus, there was no strategic effect to the potential balance of the British fleet against the devastated French fleet even had the Napoleonic Wars continued after 1814.
News of Napoleon's defeats and abdication couldn't reach the convoys and battle fleets on time, resulting only in battles with the strategic consequence of virtually eliminating the French Navy. What was significant was the effective annihilation of many French 1st rate battleships, the Bucentaure class [with its single remaining half-relative] and foreign built ships of the line from the French navy. Even the Temeraire class was badly decimated by the battle, along with 10 French frigates [all 8 of the Mediterranean Squadron and 2 from captures by the blockade] as a result of the ill fated sorties. The latter would ruin attempts by France to form a large frigate and overseas fleet for the 1st decade after 1814. This was compounded by the cessation of many foreign built, Temeraire and Bucentaure-class ships to the Netherlands, British and Habsburg Empire in the 1814 armistice.
[Apart from retaining 1792 borders while retaining constraints on French naval ship construction, the basic consequences [for the Congress of Vienna and 1st few years after] are similar to reality. The most significant consequences are no 'Hundred Days'; which will likely end with similar consequences to its actual counterpart if it still occurs, and a weaker French navy and colonial venture, both in appeal and action.]
After the defeats Napoleon faced at Trafalgar, Iberia, Russia, Germany, the world's oceans and seas and even his home; the final destruction of his navy would bring a negative reputation just after his abdication and exile to Elba. Depressed and shocked with inflated losses and damage pronounced to him by his captors, Napoleon died on 25 September 1814 from unrecoverable infections, although rumours of murder persisted. Later, these were found to originate from a suicide attempt. [As a result, Waterloo has been butterflied away, although British history books would mention the rather indecisive but heavily devastating naval battles against France as final factors in Napoleon's end with his death weeks after the news.] To this day, counterfactuals involving these naval battles even explained possible return attempts by Napoleon had it been not for the battles or even his death, with one about him receiving his army equivalent to them at Waterloo and another in Germany being popular.
The losses of many hundreds of French sailors to death, injuries, desertion and prison [although the latter were treated and dealt with accordingly] would also demoralise the French Navy besides lost ships and reduce planned overseas expeditions with its support. Eventually, the Congress of Vienna would cede Guadeloupe to Sweden and Madagascar became a British territory for the 19th and 20th centuries, along with Reunion, the Seychelles and Mauritius. However, the French temporarily obtained southern Madagascar and permanently regained Reunion in 1896 as they felt that they needed Indian Ocean bases when Egypt became unusable for trade. Also, Tunisia became an Italian [state] colony in this scenario with the French being newer to Algeria and Morocco was left independent albeit an effective puppet of Germany. [Final dismantling of the Ottomans and the actual WW1 being butterflied, intervention in Indochina to gain prestige and secure its fellow citizens and co-religionists still undertaken on different dates and Pacific plus some African colonies going to other powers if colonized by France after 1815 in reality.]