Would it be possible to add a "jump to page" button (or at least a "jump to last page" button) to the mobile topic view?

That I know of? No. But I'm sure there's some line of code within the skin templates. Check your main skin's "Topic View" and see if there is anything to do with "page jumping". if there is lines of code for it, copy it and find that same part in the Mobile skin and paste the code. ;)

EDIT: Here is the "Next Forum" jump code:

		<a href='{parse url="showforum={$forum['id']}" template="showforum" seotitle="{$forum['name_seo']}" base="public"}' class="ipsType_small desc">{parse expression="sprintf( $this->lang->words['go_back_to'], $forum['name'] )"}</a>

		<if test="hasUnreadNext:|:$forum['_hasUnreadTopics']">

			· <a href='{parse url="showtopic={$topic['tid']}&amp;view=getnextunread" template="showtopicnextunread" seotitle="{$topic['title_seo']}" base="public"}' class="ipsType_small desc">{$this->lang->words['goto_next_unread_topic']}</a>

		</if>

	</div>	

</div>

Edited May 17, 201213 yr by Im#NuMBeR1